This is Zephyr Tiger. He is a big tiger boy. He lives with Mommy, Daddy, and his little brother Auggie.

Auggie has a red toy. He likes it a lot. He has it with him. "Come, Auggie!" said Zephyr. "Let's go!"

They went to the big tree. Auggie had his toy. Then the toy went into the brush. Auggie was sad.

"Do not be sad, Auggie," said Zephyr. "I can find it. I am a big brother." Zephyr went into the brush. He looked and looked.

A little duck came up. "I can see the toy!" said the duck. "It is under that big rock."

Zephyr looked under the rock. Here was the red toy! "I have it!" said Zephyr. "Let's take it to Auggie."

"Thank you, little duck!" said Zephyr. The duck smiled. "I am glad I could help."

Zephyr ran back with the toy. Auggie jumped up and down. "Zephyr! You have it!" Auggie gave his big brother a hug.

Mommy and Daddy came over. "Zephyr, we love you!" said Mommy. Daddy gave Zephyr a big hug.

They all walked home together. The sky turned soft and pink. Auggie held his toy. Zephyr held Mommy's paw.

Then they went to sleep. Auggie had his toy. Zephyr had Mommy and Daddy. What a good day.

The next morning, Auggie smiled big. "You are the best big brother." Zephyr hugged him tight. And they played all day long.

Zephyr Tiger went to the library.

Mommy Tiger showed Zephyr the books.

Zephyr Tiger picked a red book.

Daddy Tiger found a train book.

Auggie Tiger looked at a baby book.

Zephyr Tiger sat on a soft rug.

Mommy Tiger read the red book.

Zephyr Tiger used his quiet voice.

The family took books home.

Zephyr Tiger waved goodbye to the library.

At home, Daddy Tiger read the red book to Zephyr.

Zephyr Tiger loved the library. He could not wait to go back.

Daddy Tiger dug a soft hole.

Zephyr Tiger put the seed in.

Mommy Tiger covered the seed.

Zephyr Tiger gave it water.

Auggie Tiger watched from the blanket.

A green sprout came up.

The sprout grew yellow flowers.

A butterfly came to the flowers.

Zephyr Tiger picked one flower.

He gave the flower to Mommy.

Soon the whole garden bloomed.

Zephyr Tiger loved his garden.

Zephyr Tiger saw a red fire truck.

Daddy Tiger showed Zephyr the hose.

Mommy Tiger found a yellow helmet.

Zephyr Tiger sat in the truck.

Auggie Tiger looked at the bell.

Zephyr Tiger rang the little bell.

The truck light went blink blink.

The family waved to the truck.

Zephyr Tiger tried on the helmet.

Zephyr Tiger waved goodbye.

Then the family drove home.

Zephyr Tiger dreamed of fire trucks.

This is Zephyr Tiger. He is going to Seaside. Mommy had Auggie. Daddy went with them.

At Seaside, the sun was up. The sand was hot. Zephyr ran on the sand. Auggie sat with Mommy.

Mommy had a bag. Daddy had a big red toy. "Let's go to the shore," said Mommy.

The waves came in. The waves went back. Zephyr jumped. Auggie had fun.

Daddy said, "We can swim." Zephyr can swim with Daddy. Auggie sat with Mommy on the sand.

Then Zephyr made a sand castle. He made it big and tall. "Look at my castle!" said Zephyr.

Zephyr looked for shells. He found pink ones and white ones. He gave a shell to Auggie.

Auggie had the red toy. Then the toy went into the sand. "I can find it," said Zephyr.

Zephyr looked and looked. Here was the red toy! "I have it!" said Zephyr.

Auggie gave Zephyr a hug. Mommy gave Zephyr a kiss. Daddy said, "Big brother."

The sun went down. It was time to go home. "Bye, sea," said Zephyr. "I love Seaside."

At home Zephyr had sand on his feet. He went to sleep with a big happy smile.

Zephyr saw the breadboard. It had rows for little parts.

Red was for power. Blue went back again.

A resistor slowed the power. The led did not get too much.

The led was a little light. The long leg got power.

Zephyr pushed the button. The light went on.

The circuit made a loop. Power went out and back.

Daddy added a buzzer. Buzz buzz went the sound.

Daddy turned the little knob. The light got dim and bright.

Zephyr saw the color light. Red, green, and blue glowed.

Daddy Tiger pushed the cart slowly.

Zephyr Tiger saw red strawberries.

Mommy Tiger put strawberries in the cart.

Zephyr Tiger picked yellow bananas.

Daddy Tiger found a loaf of bread.

Mommy Tiger found cold milk.

Auggie Tiger looked at the apples.

Zephyr Tiger helped put food on the belt.

Daddy Tiger paid for the food.

Zephyr Tiger helped carry the bags.

Zephyr Tiger helped put the food away.

Then everyone ate strawberries together.

Zephyr Tiger saw rain on the window.

Mommy Tiger gave Zephyr his yellow rain coat.

Daddy Tiger found Zephyr's red rain boots.

Auggie Tiger watched from Mommy's lap.

Zephyr Tiger stepped into a little puddle.

The puddle went splash under his boots.

Daddy Tiger held the big blue umbrella.

Mommy Tiger showed Zephyr a tiny snail.

Then the sun came out over the trees.

Zephyr Tiger saw a rainbow and smiled.

Then they went back home to get warm.

Now Zephyr Tiger loves the rain.

This is Zephyr Tiger. He is in the shop. Mommy had Auggie. Daddy had wood.

Daddy had a tree. He had a log. He had saws. The saws cut the log.

The machine saws wood. It can cut. Zephyr did not go near it.

The log made a plank. The plank was a board. The board was on the floor.

Zephyr held a tape. He put it on the board. Daddy made a mark.

The board was jagged. It was not smooth. Daddy made it smooth.

Mommy had a shim. The shim went under the board. Now the board did not rock.

The floor was wood. It was a wooden floor. Zephyr sat on the smooth board.

Auggie sat with Mommy. Zephyr had a board. Daddy said, "It is smooth."

Zephyr made a little box. He put Auggie's blocks in it. Everyone said, "Good job!"

Then they went home. Zephyr had his smooth board. He gave it to Mommy and Daddy.

Zephyr put the board by his bed. He went to sleep with a big smile.

It was a sunny day. Zephyr Tiger drove to Dollywood with Mommy, Daddy, and Auggie. Zephyr saw big rides and little rides. He jumped up and down.

First they rode the Great Tree Swing. The big swing went back and forth. Zephyr held on. Daddy held on too. The swing went up, then back down.

Then came Frogs and Fireflies. The frogs went round and round. Zephyr rode a green frog. Mommy waved. Auggie clapped from her lap.

After the frogs, the family took a water break. Mommy helped Auggie drink. Daddy gave Zephyr his cup.

Next came Dragonflier. It went fast like a dragonfly in the air. Zephyr rode with Daddy. He felt the wind and gave a big smile.

Then they found The Mad Mockingbird. The bird ride went up and out. Zephyr rode with Daddy. The bird dipped and soared. Zephyr laughed.

After that came the merry-go-round. Zephyr sat on a horse that went up and down. Mommy stood by him. Daddy held Auggie. The music went round and round.

Next was The Scrambler. The little cars turned this way and that way. Daddy sat with Zephyr. They slid to one side, then back again.

Then came the flying elephants. Zephyr went up and down in the sky. Daddy sat beside him. Mommy and Auggie watched and waved.

When the rides were done, the family watched the lights come on. Zephyr yawned. Mommy hugged him. The whole park glowed warm and bright.

Then they drove home in the dark. Zephyr was tired and happy. Mommy and Daddy smiled in the front. Auggie slept in his car seat.

At home, Mommy tucked Zephyr into his cozy bed. He hugged his blanket and dreamed about his wonderful day at Dollywood.

Zephyr Tiger rode the big tree swing.

Zephyr Tiger rode a green frog.

The tiger family stopped for cold water.

Zephyr Tiger felt the wind on Dragonflier.

Zephyr Tiger laughed on the mockingbird ride.

Zephyr Tiger sat on the merry-go-round.

Zephyr Tiger spun with Daddy Tiger.

Zephyr Tiger flew in an elephant.

Zephyr Tiger rode the train around the park.

The tiger family shared a yummy snack.

Zephyr Tiger waved goodbye to the park.

Zephyr Tiger fell asleep, tired and happy.

Zephyr Tiger saw the dirty car.

Daddy Tiger drove the dirty car to the car wash.

The big brushes went round and round.

Soap went on the car.

Zephyr Tiger saw many bubbles.

Auggie Tiger sat in his car seat and clapped.

Mommy Tiger wiped one small spot.

The car was clean and shiny.

Zephyr Tiger helped dry the shiny car.

The tiger family waved bye to the car wash.

The tiger family drove home in the clean car.

Zephyr Tiger loved the shiny clean car.

Zephyr Tiger saw the big slide.

Daddy Tiger pushed Zephyr on the swing.

Mommy Tiger held Auggie on the bench.

Zephyr Tiger climbed up the steps.

Zephyr Tiger went down the slide.

Auggie Tiger clapped on Mommy's lap.

The family dug in the sand.

Zephyr Tiger found a red ball.

Zephyr Tiger threw the ball to Daddy.

Everyone sat down to rest.

The tiger family waved goodbye.

And Zephyr Tiger fell fast asleep.

Zephyr Tiger saw the blue train.

Daddy Tiger held Zephyr's paw.

Mommy Tiger carried Auggie up the step.

The family sat by the window.

The train went click clack.

Zephyr Tiger looked out at the trees.

Auggie Tiger waved from Mommy's lap.

Daddy Tiger found the red seat.

The family shared a snack on the train.

The train slowed down and stopped.

The family waved bye to the train.

The tiger family went home happy.

Zephyr Tiger saw the blue pool.

Daddy Tiger held Zephyr in the water.

Zephyr Tiger kicked his feet.

Mommy Tiger held Auggie by the pool.

Zephyr Tiger blew bubbles.

Zephyr Tiger held the yellow board.

Zephyr Tiger swam a little way.

Zephyr Tiger jumped to Daddy. Splash!

Zephyr Tiger climbed up the steps.

Mommy Tiger wrapped Zephyr in a towel.

The tiger family clapped for Zephyr.

Now Zephyr Tiger loves to swim.

Zephyr Tiger saw the green trees.

Daddy Tiger found a smooth rock.

Mommy Tiger showed Auggie a leaf.

Zephyr Tiger looked at a small bug.

Zephyr Tiger heard the creek.

Daddy Tiger helped Zephyr step over the log.

Auggie Tiger clapped at the butterfly.

Zephyr Tiger put leaves in a pile.

Zephyr Tiger smelled a pretty flower.

The family rested under a big tree.

The tiger family walked home together.

What a happy nature walk!

Zephyr Tiger saw the red kite.

Daddy Tiger held the kite string.

The wind lifted the kite.

Zephyr Tiger ran on the grass.

Mommy Tiger held Auggie on the blanket.

The kite went high in the sky.

Zephyr Tiger pulled the string.

The kite came back down.

Zephyr showed Auggie the kite.

The tiger family went home happy.

The family rested at home.

What a fun kite day. Good night, Zephyr.

Zephyr Tiger saw toys and trash.

Daddy Tiger found the red bin.

Zephyr Tiger put toys in the bin.

Zephyr Tiger picked up the trash.

Mommy Tiger folded the blue blanket.

Auggie Tiger sat on the rug.

Zephyr Tiger put books on the shelf.

Auggie Tiger gave Zephyr a block.

Zephyr Tiger wiped the little table.

The room was clean and bright.

The family came to see the clean room.

The happy tigers all cleaned up together.

Zephyr Tiger saw the vegetables.

Mommy Tiger put carrots on the plate.

Daddy Tiger gave Zephyr a fork.

Zephyr Tiger smelled the broccoli.

Zephyr Tiger took one little bite.

The carrot went crunch crunch.

Auggie Tiger clapped in his chair.

Zephyr Tiger ate the green peas.

Mommy Tiger said, good job Zephyr!

Zephyr Tiger wanted more carrots.

Zephyr Tiger ate every vegetable up.

The tiger family had a happy dinner.

Zephyr Tiger saw the breadboard.

Daddy Tiger showed the red power rail.

The resistor kept the led safe.

The long led leg touched power.

Zephyr Tiger pushed the button.

The circuit made one loop.

The buzzer made a sound.

The little knob changed the light.

Red, green, and blue glowed.

Zephyr Tiger saw the red barn.

Daddy Tiger saw little chicks.

Mommy Tiger held Auggie by the fence.

Zephyr Tiger saw the green tractor.

Daddy Tiger sat on the tractor.

Zephyr Tiger fed hay to the cow.

Auggie Tiger saw a little hen.

Zephyr Tiger put hay in the barn.

The tiger family had a picnic on the grass.

They waved bye to the farm animals.

The tiger family left the farm at sunset.

The happy tiger family was home at last.

Zephyr Tiger saw the yellow digger.

Daddy Tiger held Zephyr's paw.

Mommy Tiger held Auggie by the fence.

The yellow digger scooped the dirt.

Zephyr Tiger saw the orange truck.

The dirt went into the truck.

Auggie Tiger sat with Mommy Tiger.

Zephyr Tiger patted the smooth dirt.

The orange truck drove the dirt away.

Zephyr Tiger waved at the digger and truck.

The tiger family walked away from the site.

At home Zephyr Tiger dreamed of the digger.

Zephyr Tiger saw a blue pond. The water was still.

Mommy Tiger held Auggie. Auggie saw a yellow duck.

Daddy Tiger found a smooth rock. Zephyr Tiger held the rock.

Zephyr Tiger saw green reeds. A dragonfly flew by.

Mommy Tiger pointed to a frog. The frog sat on a lily pad.

Daddy Tiger sat on the grass. Zephyr Tiger sat beside him.

Auggie Tiger clapped for a turtle. Mommy Tiger held him close.

Zephyr Tiger saw one wrapper. Daddy Tiger put it in the bin.

The tiger family walked home. Zephyr Tiger said bye to the pond.

Zephyr Tiger told Mommy Tiger about the pond. She smiled.

The tiger family sat by the pond one more time. The sun went down.

Zephyr Tiger smiled. It was the best pond day.

The tiger family went to church. Zephyr Tiger saw the big door.

Mommy Tiger held Auggie. Auggie looked at the big door.

Zephyr Tiger sat in a big chair. Daddy Tiger sat beside him.

The family sang a soft song. Zephyr Tiger sang too.

Zephyr Tiger saw big lights. The colors were red and blue.

Mommy Tiger folded her paws. Zephyr Tiger folded his paws too.

Daddy Tiger opened a little book. Zephyr Tiger looked at it.

Auggie Tiger sat on Mommy's lap. Mommy Tiger held him close.

Zephyr Tiger picked up a paper. Daddy Tiger put it in the basket.

Zephyr Tiger went down the big slide. Church was fun.

The family walked to the car. Zephyr Tiger waved bye to church.

At home the family hugged. Zephyr Tiger loved church day.

The tiger family went to the zoo. Zephyr Tiger was so happy.

Zephyr Tiger saw a big elephant. The elephant ate green leaves.

Zephyr Tiger saw a big tiger. The big tiger looked like Daddy.

Auggie Tiger saw a pink bird. Auggie clapped and clapped.

A turtle swam in the water. Zephyr Tiger watched it swim.

An eagle soared over the trees. Zephyr Tiger looked up and up.

Zephyr Tiger fed a little goat. The goat ate the food fast.

Mommy Tiger showed Auggie an owl. The owl said hoo hoo.

The family sat down to eat. Zephyr Tiger had meat and carrots.

Zephyr Tiger saw little fish. The fish swam round and round.

The tiger family waved bye to the zoo. It was time to go home.

At home Zephyr Tiger fell asleep. He dreamed of a happy zoo day.

Zephyr Tiger went fishing with Daddy. Mommy and Auggie came too.

Daddy Tiger held a big rod. Zephyr Tiger held a little rod.

Zephyr Tiger sat on the shore. The water was still and blue.

A duck swam by the reeds. Zephyr Tiger said hi to the duck.

Mommy Tiger sat with Auggie. Auggie watched the little waves.

The little rod went down. Zephyr Tiger had a fish.

They pulled and pulled. The fish came up with a splash.

The fish was big and shiny. Zephyr Tiger smiled and smiled.

Auggie Tiger clapped for Zephyr. Mommy Tiger smiled too.

Daddy Tiger cooked the fish on the fire. The family ate fish and peas.

The sun went down by the water. The family walked home together.

Zephyr Tiger went to bed happy. He dreamed of the big fish.

The tiger family walked into the woods. The sun was going down.

Daddy Tiger made a little fire. The fire glowed red and gold.

The family sat by the fire. They ate meat and carrots.

Auggie Tiger sat on the soft blanket. Mommy Tiger held him close.

Little fireflies glowed in the dark. Zephyr Tiger watched the little lights.

An owl said hoo hoo. Zephyr Tiger said hoo hoo too.

The moon came up over the trees. The moon was big and bright.

Zephyr Tiger looked at the moon. Daddy Tiger sat beside him.

Zephyr Tiger slept by Mommy and Daddy. Auggie Tiger slept too.

The sun came up and the dark went away. A little bird sang a soft song.

The tiger family walked home down the soft path.

That night Zephyr Tiger closed his eyes. He dreamed of the big bright moon.

Zephyr Tiger found a big pot. The pot was his drum.

Zephyr Tiger patted the drum. The drum made a big sound.

Mommy Tiger rang a little bell. The bell made a little sound.

Auggie Tiger found a little pot. Auggie patted it and clapped.

Daddy Tiger sang a song. His voice was big and deep.

Zephyr Tiger sang with Daddy. They sang of the sun and the moon.

Zephyr Tiger spun round and round. The music made him happy.

Auggie Tiger clapped for the music. Mommy Tiger smiled and sang.

The family made music. The music was fun.

Then the music got quiet. Mommy Tiger sang a soft song.

Zephyr Tiger went to his bed. Mommy and Daddy tucked him in.

Zephyr Tiger fell asleep. He dreamed of the happy music.

Zephyr Tiger had a little toy train. He loved his train.

Auggie Tiger came to see the train. He picked it up with his little paws.

The train fell down. The train broke.

Zephyr Tiger was so sad. He was mad at Auggie too.

Auggie Tiger looked down. He was little and sad.

Mommy Tiger held Zephyr close. You can love him when you are mad, she said.

Zephyr Tiger went to Auggie. He gave Auggie a big hug.

I love you, said Zephyr Tiger. Auggie Tiger smiled a big smile.

Daddy Tiger helped Zephyr. They made the train go again.

Zephyr Tiger let Auggie see the train. The train went round and round.

Now Zephyr Tiger and Auggie Tiger played with the train together.

Zephyr Tiger loved his train. But he loved Auggie most of all.

The tiger family went for a walk. Zephyr Tiger heard a little sound.

A little duck sat by the path. The duck said quack quack.

The little duck was lost. The duck looked sad.

Zephyr Tiger patted the duck. We will help you, he said.

Zephyr Tiger looked for the nest. The nest was not on the path.

Daddy Tiger looked by the trees. Mommy Tiger looked by the creek.

Zephyr Tiger saw the pond. He saw a nest in the reeds.

The mother duck was in the nest. Quack quack, said the mother duck.

The little duck ran to the nest. The little duck was home.

The mother duck held her little duck close. Zephyr Tiger was so happy.

Bye bye little duck, said Zephyr Tiger. The duck said quack quack.

The tiger family walked home. Zephyr Tiger felt happy and proud.

Zephyr Tiger has a ball. The ball is orange.

Daddy Tiger can help. They look at the hoop.

Zephyr Tiger taps the ball. It goes up and down.

Daddy lifts Zephyr up high. Now he can reach.

Zephyr Tiger throws the ball. The ball goes up.

The ball did not go in. Zephyr Tiger tries again.

This time the ball goes in. Zephyr Tiger did it!

Daddy Tiger is proud. They give a big high five.

Mommy and Auggie clap. They yell, yay Zephyr!

Zephyr shares the ball. Auggie pats it and laughs.

The whole family plays ball together. They all take turns.

The sun goes down. It was a fun day. Good night, tigers!

The tiger family went to space camp. Zephyr Tiger was so happy.

Zephyr Tiger saw a big rocket. It was tall and white.

Daddy Tiger showed him a moon rock. Zephyr Tiger held it.

Zephyr Tiger put on a space suit. He looked like a real spaceman.

He sat in the rocket seat. He held the controls.

Mommy Tiger and Auggie waved. They said, go Zephyr go!

Three, two, one, blast off! The rocket went up high.

Zephyr Tiger floated in the rocket. It was so much fun.

Zephyr Tiger saw the stars. He saw the round moon.

Zephyr Tiger flew back home. The family was so proud.

At home Zephyr Tiger told them all about space.

Zephyr Tiger fell asleep. He dreamed of the stars.

Zephyr Tiger sees the trash. The can is full.

Zephyr Tiger wants to help. He is a big cub.

Daddy Tiger ties the bag up. Zephyr holds it tight.

Zephyr pulls the bag out. He pulls and pulls.

The bag is big. Zephyr is strong.

The big can is outside. Zephyr opens it up.

Zephyr puts the bag in. It fits just right.

The lid goes down. The bin is shut tight.

Daddy Tiger gives a high five. Great job Zephyr!

Mommy Tiger and Auggie smile. Zephyr did a good job.

The trash is all gone. The whole family is proud.

Now Zephyr can play. What a good day!

Zephyr Tiger goes to the book store. It is full of books.

So many books are here. Big ones and small ones.

Zephyr Tiger looks at the books. He sees a red one.

Daddy Tiger reads to Zephyr. They sit and look.

Zephyr turns the pages. He sees a little dog.

Zephyr picks a book. He likes it a lot.

Mommy Tiger holds baby Auggie. Auggie looks too.

Auggie pats a soft book. He laughs.

Zephyr hugs his new book. He is so happy.

They pay for the book. Then they go home.

Zephyr reads his book at home. He loves every page.

Now Zephyr reads to baby Auggie. What a good day.

Zephyr Tiger got a shiny new bike.

Daddy Tiger helped with the helmet.

Zephyr Tiger sat on the seat.

Daddy Tiger held the bike steady.

Zephyr Tiger pushed the pedals.

Mommy Tiger cheered with Auggie.

Zephyr Tiger rode down the path.

He rang the little bell. Ding!

The wind felt good. He went a little faster.

Zephyr Tiger rode back to his family.

The tiger family was so proud.

Good night, little bike. What a happy day!

Zephyr got a new board. It was bright blue.

Daddy took Zephyr to the park. Auggie came too.

Zephyr put on his helmet. Now he was safe.

Zephyr saw a big ramp. It went up and down.

Zephyr stood on the board. Daddy held his paw.

The board can roll. Zephyr can skate!

Zephyr went up the ramp. Up, up, up!

Then he rolled down fast. Wheee!

Then Zephyr fell down. But he did not cry.

Daddy helped him up. "You can do it," said Daddy.

Zephyr got back on. He did not fall!

Mommy and Auggie cheered. What a fun day!

Zephyr had a red ball. He played in the sun.

Two bad tigers hid by the tree. They wanted the ball.

The bad tigers took the ball! They ran and ran.

"Stop!" said Zephyr. "That is my ball!"

Daddy came fast. "We will get them," said Daddy.

Zephyr and Daddy ran after the bad tigers. Run, run, run!

The bad tigers hid. But Zephyr saw tracks in the mud.

Daddy went this way. Zephyr went that way.

The bad tigers ran right to Zephyr. "Got you!" said Zephyr.

The bad tigers were sad. "We are sorry. We had no ball," they said.

"You can play with us," said Zephyr. So they all played ball.

Now the bad tigers were not so bad. They were all friends.

Zephyr Tiger went for a walk. Mommy, Daddy, and Auggie came too.

They saw a little pond. The water was blue.

Zephyr saw something on the path. It was a turtle!

The turtle was on its back. It could not get up.

"I can help," said Zephyr. "Be slow and soft," said Daddy.

Zephyr was very soft. He turned the turtle over.

The turtle looked up. It was so happy!

The turtle went slow, slow, slow. Zephyr walked with it.

The turtle got to the pond. In it went!

The turtle swam and swam. It popped up to say thank you.

Auggie clapped his little paws. "Yay, Zephyr!" said Mommy.

The sun went down. Bye bye, turtle!

"I want to build a house," said Zephyr Tiger. "I can help," said Daddy.

They got lots of wood. Zephyr helped carry it.

Daddy drew the house on paper. Zephyr looked and looked.

Daddy cut the wood. Zephyr held it still.

Tap, tap, tap! Zephyr helped Daddy build.

Up went one wall. Up went two, three, four!

Daddy put on the roof. Now it looked like a house!

Zephyr painted it red. Mommy painted the door blue.

Auggie clapped and clapped. He liked the little house.

Zephyr went in the house. It was just his size!

Mommy and Auggie came to see. "What a good house!" said Mommy.

The sun went down. Good night, little house!

Zephyr Tiger went on a trip. Mommy, Daddy, and Auggie came too.

They saw a big, big hill. It had smoke on top!

"That is a volcano," said Daddy. "Wow!" said Zephyr.

The volcano has hot rock in it. The hot rock is called lava.

Lava is red and orange. It is very, very hot.

"We look from far away," said Mommy. "Yes we do," said Zephyr.

The volcano went puff! Smoke went up, up, up.

Zephyr saw the lava. It was red like the sun.

Auggie clapped his paws. He liked the volcano too.

Zephyr found a little rock. It came from the volcano.

The family walked home. The volcano got small and far.

"I love the volcano," said Zephyr. "Me too," said Daddy.

zephyr tiger loves to run. he runs in the morning. he runs after lunch. he even runs in his dreams! his little red cap bounces on his head, bop, bop, bop.

one sunny day, daddy tiger says, "let's have a race at the park!" zephyr tiger hops and claps. "yes, yes, yes!" he shouts. off they go.

the park has soft green grass and a hill with a tall oak tree. "first one to tap the tree wins!" calls daddy tiger. zephyr wiggles his tail. ready, set, go!

thump, thump, thump! zephyr runs as fast as he can. the wind rushes past his ears. daddy tiger runs too, but he takes big, silly, slow steps.

then a strong gust of wind comes. whoosh! it lifts the red cap right off zephyr's head. it flips and floats, up, up, and away, down the hill.

zephyr stops. "my cap!" he cries. daddy tiger is far ahead. the cap is far behind. should he try to win, or should he go get it? his tummy feels wobbly.

zephyr turns around and runs the other way. zoom! there, by the little pond, he finds his cap. it is sitting on a sleepy turtle!

the turtle peeks out. "oh my," she yawns. "is this a hat for me? it is so cozy." zephyr giggles. it is much too big for a turtle!

"it is my cap," zephyr tells her. "the wind took it." the turtle gives a sleepy smile and pushes it back with her nose. "that is okay," she says. "i like leaf hats better."

zephyr pulls his cap on tight. but where is daddy tiger? there he is, by the oak tree! oh no. zephyr runs and runs, faster than ever. pitter, patter, whoosh!

daddy tiger is not touching the tree. he is waiting! "a race is more fun with you," he says. one, two, three... tap, tap! they win at the same time.

last of all, the turtle comes along in her new leaf hat. "slow and steady!" she cheers. zephyr hugs daddy tiger, and everyone laughs. what a happy day to run!

chapter one: before the sun every morning, before the sun came up, zephyr tiger heard the same sound. hup, hup, hup. that was daddy tiger going down the porch steps, saying it to his own feet. by the time zephyr tiger got to the window, the path was empty.

that night, zephyr tiger made a plan. he put his shoes on. then he climbed into bed with them still on, under the blanket, with his paws sticking out the end. mommy tiger looked in and did not say one word about it.

hup, hup, hup. zephyr tiger sat straight up. he was out of bed and out the red door before daddy tiger reached the bottom step. the sky was still grey. "well," said daddy tiger. "look who sleeps in shoes."

daddy tiger stretched his long legs, slow and careful, one at a time. then he looked up and said hup to the moon, the way he does every single morning. zephyr tiger laughed and said hup to the moon too. the moon said nothing.

then they were off. zephyr tiger shot down the path like a leaf in the wind. he passed the cattails. he passed two sleeping ducks. he looked back once. daddy tiger was not chasing. he was away back there, taking small easy steps, going hup, hup, hup.

zephyr tiger ran along mitten pond. the water was flat and pink. a fish went plip. his paws went pitter-patter, pitter-patter, pitter-patter on the dirt, and the air smelled like cold grass. he was the fastest cub in the world.

then the path tipped up by the bendy tree. "good morning, little bump," said daddy tiger, out loud, to a hill. zephyr tiger did not say good morning to it. his legs turned into two wet noodles and he sat down hard in the dirt.

daddy tiger came up the hill and sat down beside him. he held the orange bottle out to zephyr tiger first. "little legs drink first," he said. then he tipped one cold drop onto zephyr tiger's head and said, "rain." zephyr tiger laughed until he fell over.

zephyr tiger rode home on daddy tiger's shoulders. it was a good ride, but it was not what he wanted. "i went fast," he said. "you went very fast," said daddy tiger, "for about nine trees." zephyr tiger looked back and counted them. nine.

at home, daddy tiger put a small white stone in his paw. "one stone for one run," he said. zephyr tiger dropped it in the jar on the windowsill. clink. one little stone looked very lonely down there. "again tomorrow," said zephyr tiger.

chapter two: the box under the bed the rain came down all night and did not stop. no run. zephyr tiger stood at the window with his shoes on and watched the path turn into soup. "the pond is getting a drink," said daddy tiger. zephyr tiger did not think that was funny.

so zephyr tiger ran around the kitchen table instead. around and around and around. auggie tiger sat in his seat and shouted "ba!" every time he went by. mommy tiger counted. "that is fourteen," she said. "please do not get dizzy."

then auggie tiger hid a shoe, the way he always does. "look under my bed," called daddy tiger. zephyr tiger crawled under there. he found the shoe. he also found a brown box with a dented lid, pushed way back against the wall.

the box was full of paper. not writing paper. white squares with big black numbers on them, and four pins stuck in the corners of every one. zephyr tiger spread them out on the floor like a giant deck of cards.

daddy tiger came in and sat down on the floor with him, which took a while, because daddy tiger is very long. "those are mine," he said. "one for every pond run i ever ran." zephyr tiger counted them. eleven.

"what is a pond run?" asked zephyr tiger. "the whole way around mitten pond," said daddy tiger, "on the last saturday of summer. at the end there is a bell on a post. you finish, you ring it. one time, as hard as you like."

zephyr tiger stood up. "i am going to run it. i am going to ring that bell myself." daddy tiger did not laugh. he scratched his chin for a long time. "it is pretty far," he said.

they looked out the window at mitten pond. daddy tiger pointed with one claw. "around the far side, over the thumpy bridge, up big bump hill." the hill went up and up and up. "we say good morning to that one," said daddy tiger.

so here was the plan. every morning, before the sun, a little farther. first the bendy tree. then the duck sign. then the bridge, then the hill, then the bell. "that is a lot of thens," said mommy tiger from the door.

zephyr tiger slid the numbers over to one side, so there was one empty spot in the corner of the box. "that one is for me," he said. then he put the lid back on. outside, the rain stopped. he was out the red door in two seconds.

chapter three: the bendy tree the next morning, daddy tiger drew a line in the dirt with his toe. "from here to the bendy tree," he said. "no stopping." zephyr tiger looked way, way down the path at the bendy tree leaning over it. he shrugged. "easy."

zephyr tiger went. his paws went pitter-patter on the hard dirt. then he saw it. a long grey thing lying across the path, with a bumpy head. zephyr tiger stopped so fast he almost fell over, and ran back to hide behind daddy tiger's leg.

daddy tiger poked it with his shoe. it did not bite him. it did not move at all, because it was a stick. "this is a very good snake," said daddy tiger. "it has no mouth." they left it by the path.

try two. zephyr tiger ran past the stick with his eyes shut. then he opened them, and there, right by his paw, was a green beetle. a shiny one. zephyr tiger sat down to watch it walk all the way across the path.

"that was stopping," said daddy tiger. zephyr tiger told him he was only looking at a beetle. "looking at a beetle is stopping. you can look at every beetle by this pond," said daddy tiger, "after." zephyr tiger put it back in the grass.

try three. zephyr tiger did not look at the stick. he did not look at the grass. his legs got hot and his chest got tight and the bendy tree did not seem to come any closer at all. he kept going.

then the bendy tree was right there. zephyr tiger slapped the trunk with both paws and fell down in the pine needles. he had not stopped. not for the stick. not for the beetle. not even once.

daddy tiger came up saying hup, hup, hup, and then he did the bendy tree dance. he made that dance up himself. it has three moves: elbows out, knees up, one big spin. zephyr tiger got up and did it too, laughing.

then zephyr tiger stood up to go home. home was all the way back there. his legs said no. "i forgot about the back part," he said, and he sat down again in the pine needles.

that night, zephyr tiger counted the stones in the jar. six. he looked out the window. the bendy tree was not far at all, from here. the duck sign was still far. the bell was so far away he could not even see it.

chapter four: lulu says go a yellow duck was sitting under the duck sign. she had a red whistle on a yellow string around her neck. "that sign has a duck on it," she said. "i am a duck. so it is my sign." her name was lulu.

zephyr tiger asked about the whistle. "nobody lets me blow it," said lulu. "my mother says not in the house. my brothers say not at the pond. so i am saving it up for something big."

"i could say go for you," said lulu. zephyr tiger nodded hard. lulu stood up very tall, which was not very tall. she held both wings out like a grown-up. "ready. one, two, six, nine, go!"

zephyr tiger went off that line like a sneeze. the cattails flew by in a blur. his ears were flat. his paws barely touched the dirt. it was the best he had ever felt in his whole life.

he passed the snake stick. he passed the bendy tree. then, all at once, his legs went away. zephyr tiger lay down in the grass by the water and looked up at the sky, which was going around a little bit.

something came along the path, and it was not fast. waddle, waddle, waddle. zephyr tiger watched from the grass: one yellow foot, then the other yellow foot. lulu passed him without turning her head. "hello," she called, and kept waddling.

a long time later, zephyr tiger came dragging up to the duck sign. lulu was already sitting there under it, fixing her feathers. "you went fast," said lulu. she thought about it. "then you went nowhere."

"i was faster than you," said zephyr tiger. "yes," said lulu. "but i am here." she was not being mean. she said it like it was just the weather. that made it worse.

they did it again. "one, four, eleven, go!" counted lulu. and zephyr tiger took off exactly the same way. this time he did not even make it to the bendy tree. he flopped down right next to the snake stick.

"my legs only know one speed," said zephyr tiger. daddy tiger lay down in the grass beside him. "mine know two. slow for a long time, then fast at the end." lulu held up her whistle. "i say go in the real one." zephyr tiger shook her wing.

chapter five: bo never stops one afternoon, a big brown bear cub came down the path. he came very slowly. he had a blue shirt with a white stripe, and he was twice as wide as zephyr tiger. "hello," he said. "i am bo. i am training."

bo was going to be in the pond run. he had been in it twice. "i was last," said bo. "both times, and everybody was already done and drinking water." he looked at his big feet. "i just do not want to be last."

"i will run with you," said zephyr tiger. so they went. bo put down one foot. then bo put down the other foot. zephyr tiger waited. a cloud went all the way across the sky.

zephyr tiger could not stand it. he ran in circles around bo. he ran ahead and came back. he ran backwards for a while, which was a mistake, because of the rock. bo did not stop to help. bo kept going.

zephyr tiger got up and zoomed to the bendy tree. then he sat down in the needles to wait. plod, plod, plod. bo came by and kept right on going, like a slow brown truck.

so zephyr tiger zoomed past him again. he sat down by the cattails to wait again. plod, plod, plod. bo went by again. zephyr tiger's legs were getting heavy. "this is a funny kind of running," said bo.

the third time, zephyr tiger did not zoom. he could not. bo was out in front now, plodding along, and zephyr tiger was behind, and the space between them kept getting bigger. "hey," he called. "wait."

bo did not wait. "i am sorry," he called back. "i do not stop. that is the only thing i am good at." plod, plod, plod. he got smaller and smaller down the path.

they got to the duck sign at almost the same time. bo got there first, by one nose. he sat down on the rock and breathed loudly. "how do you do that?" asked zephyr tiger. bo thought hard. "i just do not stop."

on the way home, zephyr tiger tried it. slow, slow, slow, like bo. it felt terrible. it felt like running in soup. he lasted about nine trees, then he ran as fast as he could, and then he sat down.

chapter six: nell wins everything a hare came around the pond with her legs going like scissors. she had a green headband and black tips on her ears. "this is nell," said daddy tiger. nell had already run around mitten pond four times that morning.

nell had won the pond run two summers in a row. "what is it like?" asked zephyr tiger. nell thought about it. "i ring the bell. then i sit on the grass by myself and wait for everybody else to come."

zephyr tiger put his chin up. "race me to the duck sign." nell looked down at him from way up there. she did not laugh, which zephyr tiger liked. then she pulled her green headband down tight. "all right," said nell.

"do you want a head start?" asked nell. she meant it nicely. that was the worst part. "no," said zephyr tiger, and his ears went hot. "one, two, three, go," said nell, who could count.

zephyr tiger ran the best he had ever run. he did not look at the grass. he did not look at the pond. his paws went so fast they sounded like rain on a roof. he was flying.

then nell went past him. she did not even look over. the wind of her blew his ears flat and lifted the dust and dropped it again. after that, zephyr tiger was running all by himself.

zephyr tiger came puffing up to the duck sign. nell was already sitting under it with her long legs folded. "i counted nine clouds," she said. then she yawned. she tried to hide the yawn, and that was somehow worse.

zephyr tiger's face went funny. he walked around behind the duck sign where nobody could see him. then he cried, with his paws over his eyes, for a good long while. there was a chip in the bottom of the sign. he looked at that.

daddy tiger came around the sign and sat down in the dirt. he did not say it was fine. he did not say anything for a bit. "i have run that race eleven times," he said, "and i have never won it once."

"then why do you run it?" asked zephyr tiger. "because of the bell," said daddy tiger. "it is a very good bell." nell leaned around the post. "come find me in the race." zephyr tiger wiped his face and said, "again tomorrow."

chapter seven: daddy tiger is fast zephyr tiger had never seen daddy tiger really run. every morning daddy tiger stayed right beside him, taking small steps, going hup, hup, hup. "can you go faster than that?" asked zephyr tiger. daddy tiger looked down into his mug and smiled.

so they all went down to the path. mommy tiger held up the green stopwatch. auggie tiger sat up in the stroller. "to the duck sign and back," said mommy tiger. daddy tiger pulled his orange laces tight and knotted them twice.

then daddy tiger went. his long legs opened right up, all the way up, and the dust came off the path behind him in one long line. lulu duck stopped counting. even nell stopped to watch him go.

the hup, hup, hup got quieter and quieter, all the way down to the duck sign, and then it got louder again. auggie tiger put both arms straight up and shouted "ba! ba! ba!" zephyr tiger did not say anything. his mouth just hung open.

daddy tiger came back around the last bend, hardly puffing. mommy tiger clicked the green stopwatch and looked at it for a long time. "that is the fastest anybody in this family has ever gone," she said. "and i have timed every one of us."

"then why do you go slow with me?" asked zephyr tiger. "because i can only do that for one minute," said daddy tiger. "the pond run is a long, long morning. fast is the easy one. far is the hard one. you are learning the hard one."

at home, mommy tiger reached under the numbers in the shoebox and took out three more. "those are mine," she said. "i rang that bell three times, before auggie tiger came along. i was never the fastest one. i was good at the end."

then mommy tiger taught him the words. "slow legs, slow legs, long legs, long legs." zephyr tiger said it back. she made him say it again, walking. then running. then she made him say it while he stood on one foot, for no reason.

mommy tiger timed him running to the bendy tree. zoom first, then slow legs. the slow way was slower. but at the end of the slow way, zephyr tiger could still stand up. "there," said daddy tiger. "that is a cub who can go all the way around."

after that, zephyr tiger said it everywhere. in the bath. at the table. under the bed. by friday, auggie tiger was saying it too, in the only words he had. "ba ba, ba ba, ba ba, ba ba."

chapter eight: all the way around one cool grey morning, daddy tiger said, "the whole way around?" zephyr tiger had been waiting a long time for somebody to ask him that. mommy tiger came out with the green stopwatch and auggie tiger in the stroller.

they started slow. so slow it felt silly. "slow legs, slow legs," said zephyr tiger, and daddy tiger said it too, right beside him, taking exactly the same small steps. three of lulu's brothers got out of the water to watch them go by.

past the snake stick. past the bendy tree. past the duck sign, which was usually where he fell over, and his legs still worked. "long legs?" asked zephyr tiger. "not yet," said daddy tiger.

then the path came to the thumpy bridge. zephyr tiger stopped. nine grey boards, no rails, and between the boards you could see the water moving. he had crossed it before, holding a paw. never running.

daddy tiger went first. thump, thump, thump, all the way across, loud as a drum. he counted every board out loud as he went. "nine!" he called from the other side. "nine boards. now you."

zephyr tiger put one paw on board one. thump. then board two, thump, and after that he just ran, counting out loud, while the whole bridge drummed under him: thump, thump, thump, thump, thump, thump, thump. nine boards. across.

then big bump hill stood up in front of him. "good morning, big bump," said daddy tiger, and he said it like he meant it. it was the biggest hill in the world. halfway up, zephyr tiger's legs said we are finished now.

zephyr tiger thought about bo. plod, plod, plod. he made his steps very small, smaller than small, and he did not stop. not once. then the ground went flat and there was the rock on top.

from up there he could see everything: the whole mitten of the pond, the red door of his house, and mommy tiger waving a tiny arm. they did the bendy tree dance up there, on top of a hill. then daddy tiger said, "long legs."

zephyr tiger came all the way back around to the white post. mommy tiger clicked the stopwatch. the bell hung right there on its rope. zephyr tiger put one paw on the rope. then he took it off again. "not yet," he said.

chapter nine: the night before on the last friday of summer, little flags went up over the path by the house, red and yellow and blue. two white paper numbers lay on the kitchen table with their pins in them. one said four. one said twelve. tomorrow they were both running.

zephyr tiger wanted one more run, a little one. daddy tiger shook his head. "tomorrow your legs get everything." so they walked instead, slow as two snails, all the way to the bendy tree, and did the bendy tree dance in the half dark, and walked back.

at dinner nobody could eat much. "tomorrow you will be slow, and then you will be long," said mommy tiger. that was the whole speech. auggie tiger dropped his spoon on purpose eleven times.

then it was dark and zephyr tiger could not sleep. his legs kept running without him. his tummy was in a knot the size of a plum. the room was too quiet. the window was too big.

the door opened. daddy tiger folded himself down on the floor by the bed. they talked in whispers. "what if i have to stop?" asked zephyr tiger. the dark was quiet for a second.

"then i will be right behind you," said daddy tiger. "hup, hup, hup. you will hear me." zephyr tiger sat up. "no i will not. you are the fastest. you will be way out in front." daddy tiger did not say anything for a long time. "hm."

zephyr tiger put his shoes on and slept in them. in the morning he woke up before the sun all by himself. the house was quiet. nobody was running anywhere. he lay still and listened to all that quiet. then he said, out loud, "today."

mommy tiger pinned a white paper square onto his shirt with four pins, one in each corner. the number on it was four. zephyr tiger looked down at it for a long time. he was four too.

then one of daddy tiger's shoes was gone. they looked under the bed and behind the door and in the stroller. "a shoe does not just walk off," said daddy tiger. zephyr tiger looked at daddy tiger's shirt. there was no number pinned on it.

auggie tiger had the shoe on the rug, both paws around it, tight. "ba," he said. daddy tiger put it on and tied it twice. "you are not racing," said zephyr tiger. "i am running with you," said daddy tiger. "twelve can wait."

chapter ten: the pond run the chalk line was full of runners. bo was down on the ground trying to stretch and mostly rolling. nell was doing little hops on the spot. and there on an upside-down bucket, with the red whistle in her bill, stood lulu.

lulu took a huge breath and blew. nothing came out. auggie tiger shouted "ba!" and six runners took off anyway. then the whistle went peeeep, so loud that two ducks fell over, and the pond run was on.

zephyr tiger went slow. everybody went past him. nell went past like a thrown stone. and then bo went past him, plod, plod, plod, which was the worst thing that had ever happened. behind him: hup, hup, hup.

"slow legs, slow legs," said zephyr tiger out loud, to nobody. past the snake stick. past the bendy tree. past the duck sign. he was second from last and his chest hurt, and he did not stop.

the thumpy bridge came. zephyr tiger did not even slow down. thump, thump, thump, thump, thump, thump, thump, thump, thump. nine boards. one of lulu's brothers was watching from the water, and he counted along, out loud, and got it right.

then big bump hill. zephyr tiger looked all the way up it, all the way to the little flat rock on the top. "good morning, big bump," he said, out loud, to a hill. somewhere behind him, daddy tiger laughed and laughed.

he climbed in tiny steps, the bo way, and he did not stop. at the top, the whole pond was down there waiting. zephyr tiger let his legs go. long legs. he came down that hill like water out of a jug.

he passed three runners sitting in the grass. then he came up behind a wide blue back. "go on," puffed bo, and kept plodding. zephyr tiger went by. the three sitting runners were still sitting. bo had been last twice, but not today.

then somebody was coming the other way. nell, headband pushed up, her race already won, running back up the path to find him. she turned around and ran the last bit beside him, grinning. and behind them both: hup, hup, hup.

zephyr tiger took the red rope in both paws and pulled. clang. the sound rolled right across the water and came back again. that night, number four went into the box with the others. "what time tomorrow?" "same as always," said daddy tiger, "before the sun."

chapter one: how far does the sky go? zephyr tiger put his nose on the cold window. far away across the marsh, the launch pads stood lit up white. "daddy tiger," he said, "how far does the sky go?" daddy tiger looked out for a long time. "i don't know," he said. "let's find out."

that night daddy tiger joined four sheets of paper and drew the sun at one end, then the worlds in a row, and then he stopped. zephyr tiger drew a big blue question mark at the far end. "what is out there?" he asked. "nobody knows yet," said daddy tiger.

daddy tiger flies rockets. that is his job. in the morning they drove out past the marsh, and there it stood on the pad: whisker one, taller than a row of houses, white, breathing cold white mist. "count the parts," said daddy tiger.

the big stage at the bottom, with four engines. the long tank above it, full of fuel. the little capsule on top, no bigger than their car. "three," said zephyr tiger. "four," said daddy tiger. "whisker two rides up there with us. that is the one that lands."

mommy tiger brought the helmets. "nobody goes up without one." on the side of the capsule, painted as tall as zephyr tiger, was the crooked star he drew when he was three. auggie tiger kicked and kicked on her hip, and one striped sock went missing at the gate.

the elevator climbed the tower, clank, clank, clank. they walked out along the narrow walkway to the hatch, high up, with the sea shining far below. "mission control is ready," said mommy tiger, right in his ear. she was home already, at the kitchen table, holding auggie tiger.

five straps each. click, click, click, click, click. daddy tiger pointed at a row of twelve blue squares. "that is our fuel. each square is lots of pushing. a used one goes dark for good." he touched the last square. "this one brings us home. we save it for that."

"ten," said mommy tiger. "nine. eight." daddy tiger flipped up the little metal lid on the red button, and zephyr tiger put his paw on it. "three. two. one." "hold on to your whiskers!" shouted daddy tiger. zephyr tiger pressed. the whole world started to roar.

whoosh! the pad dropped away below them. the seat pushed hard into zephyr tiger's back, like one big friendly paw. the sea went small. the marsh went small. the blue sky turned dark, then darker, then black as the inside of a pocket.

bang. the roaring stopped. "the big stage has done its job, so it is going home," said daddy tiger. out the window it tipped slowly over, lit one engine, and fell away toward the sea. then the long tank lit, and the pushing began again.

"the big stage is standing on its legs by the water," said mommy tiger. then the pushing stopped. zephyr tiger's crayon floated up off his knee. so did his tail. so did his ears. "are we falling?" he asked. "yes," said daddy tiger. "we just keep missing."

"where first?" asked daddy tiger. he had stuck their paper map to the wall. zephyr tiger put his paw on the very first drawing. "the sun." so they pushed one more time, long and steady, and earth stopped curving under them and started shrinking behind them instead.

a real spaceship would take years to reach the far cold worlds. whisker one is quicker than that. it is the one thing in this book that is not true. then the engine stopped. outside there was no sound at all, because space has no air in it.

the stars did not twinkle. they sat still and sharp, like holes poked in black paper. at home they always wobble, because our air wobbles. out here there was no air to wobble. far ahead the sun waited, white and huge.

"i bet the sun is a fire," said zephyr tiger. "the biggest fire ever." "good guess," said daddy tiger. "let's go and look." closer and closer. it was not a fire. nothing was burning in there at all. the sun is a star.

"visors down," said daddy tiger, and both gold visors flipped shut. even then the light filled the whole window. "is it bigger than our house?" "zephyr tiger, every single world on our map could fit inside the sun, with lots of room left over."

the sun pulls. it pulls so hard that every world on the map has to swing around it, for ever and ever. daddy tiger unclipped the flashlight and swung it round and round on its cord. "is it holding us too?" "it is holding everything," said daddy tiger.

up close the sun had grey freckles on it. cooler spots, daddy tiger said, some of them wider than earth. and at the rim, great loops of light curled up and over and fell back in, slow and soft, like water pouring.

daddy tiger put one claw on the screen, above a heat bar that was climbing up. "when it reaches here, we turn around. that is a promise." the bar climbed. the window went white. the metal walls began to tick and ping as they swelled in the heat.

the bar reached his claw. daddy tiger did not shout. he swung a gold shade across the window, put one big paw over zephyr tiger's on the red button, and they pressed. "we stop here," he said. "we can't go any closer. only robot ships with big shields can."

then daddy tiger slid the shade back a little. zephyr tiger held one glove up in the beam. the light landed on it, warm and gold. "at home, sunlight takes eight minutes to reach us," said daddy tiger. "here, so close, it reached your paw much quicker."

zephyr tiger held very still. then he caught his crayon drifting past his ear and put a small check beside the sun on the map. "next is mercury. i bet mercury is melted, like soup." daddy tiger smiled. "good guess. hold on to your whiskers."

chapter two: the little rock that runs "the sun. mercury." zephyr tiger read the map twice, then sang it. out the round window, a small grey dot grew and grew until it was a ball. "there she is," said daddy tiger, and tapped the window twice with one claw.

mercury was not soup. mercury was grey and hard and full of holes, like the moon at home. it was the smallest planet of them all. "it is littler than i thought," said zephyr tiger. "so are you," said daddy tiger, "and look at you."

the holes were craters. rocks had come down hard, over and over, for longer than anyone can count. and because mercury has almost no air and no wind, nothing ever blew the dents away. one crater was so wide it had mountains round the rim.

mercury had wrinkles too, long ones, running right across it. "it got smaller as it cooled down," said daddy tiger, "so its skin creased up." "like an old apple," said zephyr tiger. "exactly like an old apple."

daddy tiger opened the round door in the nose. they crawled through the little tunnel into whisker two, and somewhere under the floor a pump thumped away, filling it with fuel. two small windows. four legs. one engine. "ready?" "ready."

"can we land in the sunshine?" "we can touch down," said daddy tiger, "but we cannot stay. you will see why." mercury has no air to hold a parachute, so they came down on the engine instead, slower and slower, until the legs touched. bump.

the dust they kicked up did not hang about, and it did not blow away. it fell right back down. then a fan started to scream, and the floor got too hot to put a paw on. "now you see why," said daddy tiger. "press the button."

they hopped north, over and over, to the very top of mercury, and set down in the black shadow of a crater wall. the legs began to go icy cold. "hot there, cold here," said zephyr tiger. "and nothing in between," said daddy tiger. "no air to carry the warm."

zephyr tiger switched on the yellow flashlight. the beam found something small tucked under a strap by his boot. stripes. a stretched cuff. a hole in the toe. "that is auggie tiger's sock!" he shouted, and laughed until his helmet fogged up.

they climbed down the ladder and stood in the dark. at the very top of mercury the sun does not climb the sky. it crawls along the edge of the ground. and the sky stayed black as night. "no air," said daddy tiger, "so no blue. and no moons."

"it is the fast one," said daddy tiger. "mercury runs round the sun quicker than any planet there is. a year here is shorter than three months at home." zephyr tiger thought about that. "then i would have four birthdays," he said, "every year."

at the bottom of the crater the flashlight found something white. ice. real ice, on the planet nearest the sun. "down here is so deep," said daddy tiger, "that the sun has never once shone in." zephyr tiger put a glove on it.

back in the capsule, floating again, zephyr tiger checked mercury off and tucked the sock into his pocket. "venus next. i bet venus is soft and comfy, because clouds." daddy tiger smiled a slow smile. "good guess. hold on to your whiskers."

chapter three: the planet that says no "the sun. mercury. venus." zephyr tiger sang the map, and this time he did a little dance with it. ahead, venus came up smooth and creamy and bright. "there she is," said daddy tiger, tap tap on the window.

"soft," said zephyr tiger. "i told you. look at it. it is one big pillow." and it did look soft, like the top of a quilt. daddy tiger did not say yes and did not say no. he said, "straps on. let's go in."

on the way down daddy tiger put one claw on a needle under glass. "this tells us how hard venus is squeezing. when it reaches this line, we come straight back up. that is a promise." "but we are landing." "no. nobody lands on venus."

"venus is almost exactly as big as earth," said daddy tiger. "nearly the same size. like twins." "so it will be nice, then." "earth has a moon," said daddy tiger. "venus has none at all. so they are not the same in every way."

the clouds closed over the window. the bright white went away. everything turned a dull dim orange, like looking through a paper bag. they could not see the ground. they could not see anything at all.

then the capsule began to groan. the thick air on venus leans on everything, hard, all the time, and never stops. "it is squeezing us," whispered zephyr tiger. "it is," said daddy tiger. "hold the handle." the needle crept up toward the red line.

and it was hot. hotter than mercury, even though venus sits further from the sun. the thick air works like a lid on a pot. the heat gets in and it cannot get back out, so it stays and stays and stays.

something streaked past the window. "rain!" said zephyr tiger. "not water," said daddy tiger. "that rain burns, and it never lands. it dries away in the hot long before it reaches the ground." zephyr tiger sat back in his seat.

the needle touched the line. "now!" said daddy tiger. zephyr tiger pressed the red button, and up they went, out of the orange and into the clean black. "but i wanted to stand on it!" "i know," said daddy tiger. "venus says no. venus says no to everybody."

one blue square went dark. every push had used a bit of it, and that climb used the rest. "i was wrong," said zephyr tiger. "it is not soft." daddy tiger nodded. "you guessed, then you looked. that is the whole trick. that is how anybody finds anything out."

then daddy tiger said, "here is a funny thing about venus." nearly all the planets spin the same way round. venus spins the other way, so on venus the sun would come up on the wrong side of the sky.

and venus turns so slowly. "one turn is one day, right?" "right. and one trip round the sun is one year." daddy tiger grinned. "on venus, one day lasts longer than one whole year." zephyr tiger said, "that is not allowed."

daddy tiger turned the whole ship round with the stick so they could look back. venus shone behind them, white and clean, brighter than any star in our sky. "you have seen it before. out your own window, in the evening. that bright one. that is this."

zephyr tiger checked venus off, and smudged the drawing of it with his thumb, on purpose, so it looked cloudy. "earth next," he said. "ours. i bet it looks enormous." daddy tiger looked at him kindly. "good guess. hold on to your whiskers."

chapter four: the blue one and its moon "the sun. mercury. venus. earth." zephyr tiger got to the end of the chant and stopped singing. out the window, a long way off, a small blue and white marble was turning. "there she is," said daddy tiger, very quietly.

zephyr tiger had guessed enormous. it was not enormous. he could cover the whole thing with one glove, if he held it out. everything he had ever seen was in there. he did not say anything for a while.

"why is it so blue?" "water," said daddy tiger. "more water than land. the white swirls are clouds, and the green and brown bits are the ground, where we live." zephyr tiger found the brown bit their house was on.

there were no lines on it. no names, no edges, nothing drawn anywhere. just blue and white and brown, turning slowly. and all the way around it ran one thin bright blue rim, thinner than a whisker. "that is the air," said daddy tiger.

"everything alive lives under that line," said daddy tiger, "except us two, for now. every other tiger. every bird. every fish and every tree." "and on the other planets?" "nowhere," said daddy tiger. "nobody has ever found anything alive anywhere but here."

daddy tiger pushed them into a big circle around earth, and they went round, and round, and round. every time they came out of the dark side, the sun came up again. "how many sunrises in one day up here?" "sixteen," said daddy tiger.

then zephyr tiger's chin went wobbly. "i want to go home," he said. "i want mommy tiger." he did not say it loudly. daddy tiger did not tell him not to. he said, "let's call her."

daddy tiger flipped the switch. zephyr tiger said, "mommy tiger?" and right away, crackly and small and absolutely her: "i hear you, zephyr tiger." and behind her voice, a squeak. auggie tiger.

"that was quick," said zephyr tiger. "we are close to home," said daddy tiger. "far out, her words will take longer and longer to reach us." "we are proud of you," said the radio. "now go and see the rest." zephyr tiger sat up straighter.

"are we going down?" "not today," said daddy tiger. "but there is one place close by we can stand on. hold on to your whiskers." zephyr tiger pressed the red button, and they flew out to a grey ball, pale and dusty and full of craters.

they crawled through the tunnel into whisker two and let go of whisker one. it stayed up there, going round and round the moon on its own, waiting. the moon has no air either, so down they came on the engine, slow and straight, legs first.

whisker two set down in soft grey dust. when they climbed out, the dust went up around their boots in a slow low fan and settled straight back down. no air to blow it about. and even in the daytime, with the sun out, the sky above them was black.

then zephyr tiger stopped. there in the dust were boot prints. not theirs. somebody had stood right there, a long time ago. "people came here," said daddy tiger. "they really did. and the prints are still here."

"nothing has rubbed them out. no wind. no rain. no weather at all up here." zephyr tiger put one small boot down beside the big old print and lifted it again. two prints now. his would stay too.

then he jumped. he went up and up and came down slow, like a feather in a dream. the moon is small, about a quarter as wide as earth, and it pulls much softer. daddy tiger stayed close and caught him every time.

"does the moon make its own light?" "it borrows the sun's." and look: earth hung up there and did not move. the moon keeps one face turned to earth for ever, so from here earth just stays, hanging in the same spot.

"the moon tugs our sea up and down the beach, twice a day," said daddy tiger. whisker two flew them up to whisker one. zephyr tiger checked off earth and the moon. "mars next. i bet mars is red because it is hot." "good guess. hold on to your whiskers."

chapter five: red dust, blue sunset "the sun. mercury. venus. earth. mars." the chant was getting long, which zephyr tiger liked. ahead, mars came up rusty red, with a white cap on top and a white cap underneath. "there she is," said daddy tiger. tap tap.

"told you," said zephyr tiger. "red means hot." "not this time," said daddy tiger. "down there it is freezing." mars is red for another reason: the dust is rust. the whole planet has gone rusty, like an old nail left out in the rain.

they crawled into whisker two and let go. mars has a little air. not enough to breathe, but enough to lean on. whisker two came in shield first, and the shield went pink hot. then a big parachute cracked open. then the engine lit. then four legs touched down. bump.

they climbed out. mars is about half as wide as earth, a small world, and all of it is covered in dust as fine as flour. it got on their boots. it got on their gloves. it got into every crease of their suits.

"is it cold cold?" "colder than our freezer," said daddy tiger. "most of the time. and much colder at night." zephyr tiger breathed out hard, and the inside of his helmet went white, and he thought that was wonderful.

two little moons went over, small and bright. "phobos," said daddy tiger, "and deimos. they are not round. they are lumpy, like two old potatoes. phobos is in such a hurry it crosses the sky twice before bedtime."

"and how long is a day?" "about the same as ours," said daddy tiger. zephyr tiger thought about that for a while. a whole other planet, freezing and red and far away, and bedtime there comes round at about the same time.

then the sky went brown. then it went dark. dust came rolling over the hill, thick as fog, and it hissed along the side of whisker two like somebody pouring sand. "dust storm," said daddy tiger. "in. now."

he flew them low and dropped into a crack in the ground. it was not a little crack. it was a canyon so long that back home it would reach from one side of our whole country to the other. the wind went over the top.

they waited. zephyr tiger wedged the striped sock under a strap where he could see it. daddy tiger hummed, low and steady, the way he does at home. after a while the hissing got thin, and then it stopped.

when the sky was quiet and tan again, daddy tiger hopped them to a big round crater, and they climbed out. there on the floor, something was moving. six wheels. a long neck. a square head with a camera on it, turning slowly, taking a picture of a rock.

"it is a robot," said daddy tiger. "people built it and sent it here. it drives a little way each day and sends the pictures home." zephyr tiger waved at it. it did not wave back. it had work to do.

then daddy tiger lifted them up to see the mountain. it is the biggest volcano anywhere. more than twice as tall as the tallest mountain on earth. and so wide, and sloped so gently, that from the bottom you cannot see the top.

flying on from the mountain, zephyr tiger saw curvy lines in the ground, winding along like rivers. "they are rivers," said daddy tiger. "old dry ones. water ran here, long ago. and there is still ice, in the white caps at the top and bottom of mars."

at the end of the day they sat on a rock and watched the sun go down. at home the sunset goes orange. here the tan sky turned, and round the sun it went blue. cold blue. zephyr tiger said, "it is backwards."

back in whisker one, zephyr tiger checked mars off. two more blue squares went dark as they climbed away. the next drawing on the map was lots of little dots. "rocks. i bet they are packed in tight, like a wall." "good guess. hold on to your whiskers."

chapter six: the rocks that are not a wall "the sun. mercury. venus. earth. mars. the rocks." zephyr tiger put his helmet on, shut the visor, and gripped his straps with both paws. "ready," he said, with his eyes closed. "hit us."

nothing hit them. zephyr tiger opened one eye. black. a few stars. nothing else at all. "where is the wall of rocks?" "we are in it," said daddy tiger. "we have been in it for a while now."

zephyr tiger watched the window for a long time. he watched it upside down too, in case that helped. he waited for something exciting to happen. one crumb of dust floated past. the belt of rocks, it turns out, is mostly nothing.

"there are more rocks here than anybody has counted," said daddy tiger. "but the belt is so wide that they sit miles and miles apart. you can fly through for days and meet none of them." "well," said zephyr tiger. "i was ready and everything."

daddy tiger had not lit the engine for days, and they were still going very fast. out here there is no air to rub on you. only the sun's pull slows you, a bit at a time. "then what is the fuel for?" "turning. stopping. starting. never for keeping going."

then a rock came. it slid up out of the dark, grey and lumpy and full of dents. it was not round. it looked like a peanut, if a peanut were the size of a hill. zephyr tiger said, "oh," and forgave the belt.

"what are they for?" "they are leftovers," said daddy tiger. "when the planets were being made, these bits never got stuck on. so they have been out here on their own ever since."

"could we push them all into one?" "you could," said daddy tiger, "and you still would not have a planet. squeeze every rock in the belt together and the ball you made would be smaller than our moon."

a bigger rock turned past, and something tiny went round and round it. "it has got a moon," whispered zephyr tiger. "a rock with a moon." "some of them do," said daddy tiger. "that is the best bit."

then the biggest one of all came round, and this one was round. "ceres," said daddy tiger. "too small to be a planet. there is a name for that. it is a dwarf planet." it had two white spots on it, like spilled paint.

crack! zephyr tiger's heart banged. something had hit them, hard and fast, out of the empty black. daddy tiger did not hurry. he leaned over the window and found it: one tiny white chip in the glass. one speck of dust. that was all it took.

"this window is really three windows," said daddy tiger, "one behind the other. the speck only hit the outside one." then he watched a green bar on the screen for a long, long minute. it did not move. "and our air is staying in. we are fine."

the chip had six little cracks around it, like a star. "that is my star," said zephyr tiger, and he checked the rocks off the map. "jupiter next. i bet jupiter has the biggest mountain of all." "good guess. hold on to your whiskers."

chapter seven: the storm with no ground "the sun. mercury. venus. earth. mars. the rocks. jupiter." zephyr tiger sang it. then he stopped singing, because jupiter had filled the window, and then it filled the sky, and then it filled everything.

"how big is it?" "take all the other planets," said daddy tiger. "mercury, venus, earth, mars, every one of them. you could put the whole lot inside jupiter and have room left over." zephyr tiger said nothing at all.

jupiter had stripes, wide ones, cream and orange-brown, going right round. where two stripes rubbed together the clouds curled up into swirls. and all of it was turning fast. a day on jupiter is over in about ten hours.

"so where is the mountain?" "there is no mountain," said daddy tiger. "there is no hill. there is no sand and no floor. jupiter is not made of ground. it is made of gas, a kind of air. deeper down, the gas gets squashed into hot runny stuff."

zephyr tiger did not believe it. every place has a bottom. puddles have a bottom. the bath has a bottom. "can we go down and see?" daddy tiger thought about it. "we can go and look," he said. "we cannot land."

then something began to click in the wall, quick and quiet. "jupiter throws out something we cannot see," said daddy tiger. "it would hurt us if we stayed. so we will go down once and come right back out." the clicking got faster. zephyr tiger buckled his straps himself.

they went down into the cream stripe. the clouds came round them like fog. then the fog got thick. then it got dark, and loud, a long low roaring, the way the bath sounds when your ears are under the water.

and they went faster. not flying. falling. jupiter pulls harder than anything except the sun, and there was nothing underneath to land on, only more cloud, and under that, more. the capsule tipped over on its side.

daddy tiger turned the nose up with the stick. "press it," he said, "and keep it pressed." the engine shoved them hard into their seats. up, and out, and quieter, until the roaring was far below. two blue squares went dark. daddy tiger had counted on that.

out in the black, zephyr tiger was shaking. "i was scared," he said. "me too," said daddy tiger. "that is allowed. being scared is just your body telling you to pay attention." then he held him for a bit.

then daddy tiger flew them round the side of the biggest storm there is. it is red, it spins, and it is wider than the whole of earth. "how long has it been going?" "about two hundred years," said daddy tiger. "nobody has ever seen it stop."

jupiter has moons the way a cat has fleas: dozens and dozens of them. one of them, ganymede, is the biggest moon we know of. it is bigger than the planet mercury. a moon, bigger than a planet.

then a moon went by that was the colour of mustard, splashed with white and red. "io," said daddy tiger. no craters at all. just volcanoes, hundreds of them, and while they watched, one let go: a grey-blue fountain, arching up and falling back in a wide umbrella.

next came a white one, smooth as a frozen pond, with long brown lines all over it like a cracked eggshell. "europa," said daddy tiger. "we can stand on this one." they climbed into whisker two, and down it came on its legs, soft and steady.

they lay down flat on the ice, side by side, just for a minute. "under here," said daddy tiger, "is an ocean. deep and dark, going round under all this ice. nobody has ever seen it. but we are almost sure it is there." zephyr tiger listened.

they lifted off the ice and joined the capsule. "now watch," said daddy tiger. he aimed them close past jupiter, falling faster and faster. at the closest bit, he fired the engine. a push goes furthest when you go fastest. one more square went dark. out they flew toward saturn.

jupiter stayed behind them for a long while, huge and striped and bright enough to read by. zephyr tiger checked it off. "saturn next. i bet its rings are one flat hoop, like a plate." "good guess," said daddy tiger. "hold on to your whiskers."

chapter eight: right through the rings "the sun. mercury. venus. earth. mars. the rocks. jupiter. saturn." the chant took a whole breath now. and there she was, tipped a little to one side, wearing her rings like a hat somebody put on crooked.

saturn is the second biggest planet, after jupiter, and it is the colour of butter. soft gold, with faint quiet stripes. "it looks kind," said zephyr tiger. "it is not kind," said daddy tiger. "but it does look it."

they came in close to the rings, and zephyr tiger's flat plate turned into a snowstorm. the rings are not one solid hoop at all. they are made of pieces. so many little pieces of ice and rock, all going round together.

some pieces were grains, like sand. some were snowballs. some were as big as a house. tink. tink. tink-tink-tink they went along the hull, and daddy tiger flew slow and careful, picking his way like someone crossing a stream.

they came up out of the top, looked back, and sank down level with the rings. the rings went flat. then thinner. then they were one bright hairline, almost nothing. all that, and the whole thing is thinner than the big mountain on mars was tall.

"here is a strange one," said daddy tiger. "saturn is so light for its size that if you had a bath big enough, saturn would float in it." zephyr tiger laughed for a long time about that.

at the very top of saturn the clouds do something nobody expects. they make a shape. a real shape, with six flat sides, spinning slowly round the pole. "who drew that?" asked zephyr tiger. "nobody," said daddy tiger. "the wind did."

and saturn has moons. more moons than any other planet, more than anyone can keep track of, little ones and big ones, going round and round in a crowd. "can we see one?" "we can see two," said daddy tiger.

the first was titan, wrapped in thick orange air like a lamp with a cloth over it. its air is so thick that whisker two needed no engine on the way down. just a parachute, drifting, slow as a leaf, for hours.

"a lake!" "not water," said daddy tiger. "it is far too cold here for water to be wet. on titan, water is as hard as rock. the lakes are made of something else, and it rains that too, in slow fat drops."

climbing back off titan cost two squares. four were left, and one of those had a white ring round it. the second moon was small and white, the whitest thing they had seen. near its bottom ran four long blue cracks, with fountains standing straight up.

they flew in close for a look, right through a fountain, just as daddy tiger had planned. it was far too thin to push them, only a spray of tiny bits of ice, like snow blowing off a roof. daddy tiger grinned. "it is snowing on us," he said.

whisker one came out frosted all over, white and sparkling, with ice packed into the little star in the window. zephyr tiger checked saturn off. "uranus next. i bet it spins like a top, same as all the rest." "good guess," said daddy tiger. "hold on to your whiskers."

chapter nine: the planet lying down "the sun. mercury. venus. earth. mars. the rocks. jupiter. saturn. uranus." the flight out was long and dark. the sun behind them had gone small, like a porch light down a street. then a pale blue-green ball came up, lying on its side.

"see?" said zephyr tiger. "spinning like a top." "look again," said daddy tiger. uranus was not spinning like a top. uranus was lying right over on its side and rolling, the way a ball rolls down a hill.

it had rings too, thin dark ones, hard to see. saturn wears its rings round its middle. so does uranus, but uranus is tipped right over, so from here its rings loop over the top and under the bottom. "everything here is wrong," said zephyr tiger happily.

it was cold in the capsule. properly cold. the little heater hummed all day and it was still cold. daddy tiger shook out the red checked blanket, wrapped it round zephyr tiger, and held him close. "of all the planets," he said, "this one has the coldest air."

up close, uranus had nothing on it. no stripes. no spots. no storms you could point at. just smooth pale blue-green, like a frosted marble. "it is a bit boring," said zephyr tiger. "it is the strangest one yet," said daddy tiger.

"could we stand on it?" "no. it is like jupiter that way, no floor anywhere in it. gas on the outside, and deep down a thick hot slush." zephyr tiger sighed. "nobody out here has a floor."

and because it lies on its side, the top of uranus points at the sun for years and years. summer there lasts twenty-one of our years. at the very top, the night lasts twice as long. you would be grown up before the sun came up.

"did people always know it was here?" "no," said daddy tiger. "it is so far and so dim that people who saw it thought it was just a star. somebody found it by looking through a long tube, and looking carefully, and not giving up."

then zephyr tiger looked round and could not tell which way was up. the planet lay sideways. the rings went the wrong way. the capsule turned slowly. his tummy went funny. "which way is up?" he asked.

daddy tiger gave him the real answer. "out here there is no up," he said. "there is no down either. nothing has a top." then he tapped the little dark glass eye by the nose door. "but whisker one always knows which way it is pointing. it watches the stars."

then daddy tiger turned the whole ship with the stick, slowly, until the small bright sun sat in the middle of the window, with one tiny pale blue speck right beside it. "that way is home," he said. zephyr tiger put one claw on the glass by the speck.

uranus has more than twenty moons. one of them is miranda, and miranda has the tallest cliff anywhere. whisker two set them down near the top, and they walked out and looked over. "if you fell off," said daddy tiger, "you would fall longer than a bedtime story."

back in the blanket, zephyr tiger checked uranus off. two drawings left on the map before the question mark. climbing off miranda cost one more square, so nine were dark now. "neptune. the last planet. i bet the last one is the quietest." "good guess. hold on to your whiskers."

chapter ten: where the wind never stops "the sun. mercury. venus. earth. mars. the rocks. jupiter. saturn. uranus. neptune." ten things now. ten. ahead of them hung the last planet of all, pale blue, a little bluer than uranus, with a few white streaks across it.

"quiet," said zephyr tiger. "i can tell." then he saw the white streaks move. they were not streaks. they were clouds, running. neptune has the fastest wind of all the planets. faster than a big plane. faster than any wind at home.

"one dip," said daddy tiger, "and then out." they dropped into the top of that wind and it took them. sideways. fast. in a long white smear of cloud, with the hull howling and daddy tiger holding the stick in both paws.

then they were out and climbing, and one more blue square went dark. everything loose was somewhere new. the blanket had moved. the crayon had moved. and the little striped sock was gone. zephyr tiger looked everywhere twice. no sock.

"in here," said daddy tiger, "things that go missing all end up in the same place." he went down by the floor, to the little round grille where the fan pulls the air through. and there it was. stuck flat against it, waiting.

he peeled it off with one claw and passed it over. zephyr tiger held it in both paws, hard. "i was not scared for me," he said. "i was scared for the sock." "i know," said daddy tiger. "that is why i went and looked."

out past the clouds it was dim. not night. not day either. like the last bit of evening, all the time. and the sun was a tiny fierce point now, too small to look like a ball at all.

"how long is a year here?" daddy tiger started counting on his claws, ran out of claws, and laughed. "longer than a hundred of ours. the people who found neptune are long gone, and it has only gone round the sun once since then."

"and here is the best thing. before anybody knew neptune was there, somebody worked out where it had to be. with a pencil. on paper. then they pointed a telescope at that exact spot, and there it was." zephyr tiger thought that was better than magic.

neptune has thin dark rings too, easy to miss. its big moon is triton, pink and white and dimpled like the skin of a melon. it goes round neptune backwards, the other way from how neptune spins. and little dark fountains shoot up out of its ice.

they floated with the map held between them. one little circle after neptune, and then the question mark. "is the end of the sky after pluto?" asked zephyr tiger. daddy tiger looked at the blue question mark for a while. "i don't know," he said.

zephyr tiger took a breath. "let's find out," he said. and this time it was him who said it. daddy tiger did not say anything for a moment. then he put one paw on top of the cub's head.

neptune's own pull swung them round and sent them on, out past the last planet. it cost nothing at all. two squares were left now. one to spend. and one with the white ring round it.

zephyr tiger checked neptune off and tucked his crayon behind his ear. "pluto next," he said. "i bet pluto is a planet. a very little one." "good guess," said daddy tiger. "hold on to your whiskers."

chapter eleven: the little heart at the edge "the sun. mercury. venus. earth. mars. the rocks. jupiter. saturn. uranus. neptune. pluto." eleven. the chant needed two breaths now. out in the dim came a little ball of tan and cream. "there she is," said daddy tiger. tap tap.

"a planet!" said zephyr tiger. "the littlest one." "no," said daddy tiger. "pluto is not one of the eight planets. it is a dwarf planet. there are others out here like it." "is that a sad thing?" "it is just the true thing."

pluto is smaller than our own moon. and on the side facing them, pale against the rust, lay an enormous heart. "who made that?" "the cold did," said daddy tiger. "out here even the air freezes. it fell like snow and settled in that shape."

going down and coming back up would spend the square before the last one. "press it," said daddy tiger, and zephyr tiger pressed. down they came, right on the heart. the ground creaked under their boots: rock underneath, ice on top.

the ice was moving. not fast. so slow that you could stand still and never see it. "it flows," said daddy tiger, "like a river, but only as fast as your claws grow." zephyr tiger stood very still and tried to feel it.

the sun was up. it did not look like it. it was one bright dot, and the light it sent was as dim as the evening, just after the sun goes down. "it is still enough to read by," said daddy tiger. "just not enough to look like day."

pluto has five moons, and charon is the big one. charon is so big that pluto cannot swing it round on its own. the two of them swing each other, round and round, like two tigers holding paws and spinning.

"can we call mommy tiger?" daddy tiger looked at the little blue speck. "we can send it now," he said. "she will hear it this evening. and we will hear her back when you are asleep." out here, words take hours.

so zephyr tiger said it anyway. "mommy tiger, we are standing on the heart." then they waited, and ate, and slept. and when he woke, her voice was on the radio, small and far away. "i heard you. keep going."

whisker two took them back up to the capsule. "what is after pluto?" "more of this," said daddy tiger. "a huge wide ring of icy worlds, going round out here in the dim, more than anybody has counted. pluto is one of them. nobody has seen most of them yet."

one came close enough to see: a lumpy ball of dark ice and dust, no bigger than a mountain. "a comet," said daddy tiger. "fall in toward the sun and the sun cooks you, and you grow a shining tail that always points away from the sun."

"you have seen a bit of one," said daddy tiger. "comets drop crumbs all along their way. when a crumb hits our air it burns up in a streak. that is a shooting star. you wished on one in the yard."

zephyr tiger looked out at the dark past the comet. "so where does it end?" daddy tiger took a long time. "nobody has found an end," he said. "not one. the sky just keeps going, and going, and nobody knows how far."

then daddy tiger let whisker two go. the ships came apart with a soft thump. "lighter goes further," he said, "and it has done its job." the little lander drifted away, out past pluto, still flying. zephyr tiger waved.

zephyr tiger checked pluto off. after it the map was blank, all the way to his question mark. "what do i bet?" he said. "i don't know what to bet." "neither do i," said daddy tiger. "hold on to your whiskers."

chapter twelve: we will need more paper "the sun. mercury. venus. earth. mars. the rocks. jupiter. saturn. uranus. neptune. pluto." then zephyr tiger stopped, because the next thing on the map was his own blue question mark, and nobody had anything to put after it.

"the last square is still there," said daddy tiger. "it will take us home whenever you say. and we can stay out here a little while first, if you like." he did not say which he wanted. "you tell me when," he said.

"what is further out?" "out past us," said daddy tiger, "the wind that blows off the sun gets thin, and then it stops. that is the soft edge of the sun's wind. but even far, far past that, the sun is still holding on to little icy bits."

"did anyone go through it?" "not anyone. something. people built a little machine and sent it out that way, long before you were born, and it is still going. nobody is driving it. it just keeps flying." "like whisker two," said zephyr tiger.

"and those?" zephyr tiger pointed at the little hard lights. "those are suns," said daddy tiger. "every one. but they are so far that whisker one could fly for your whole life and never reach the nearest one." "so not tonight." "not tonight."

zephyr tiger looked out at the dark for a long time. it went on and on, and nobody knew if it ever stopped. then he looked at the little pale blue speck instead. "home," he said. "that one has mommy tiger in the window."

daddy tiger flipped up the metal lid. the last blue square sat there with its white ring, just as it had since the pad. "this one was always yours," he said. "hold on to your whiskers. three. two. one." zephyr tiger pressed.

it was the longest push of the whole trip. the engine shoved and shoved for a long, long time, and when it finally went quiet the dark was behind them and the small fierce sun was straight ahead. the last square went dark.

and then the worlds came past again, the other way round. "pluto," said zephyr tiger. "neptune. uranus. saturn. jupiter. the rocks. mars." each one brighter than the one before. the dim went away. the sun grew back into a ball.

and mommy tiger's voice came closer in his ear. out at pluto her answers took hours. then one hour. then minutes. then seconds. and close to earth she answered him almost as quickly as if she were in the next room.

near home, daddy tiger let the long tank go. it had nothing left in it anyway. it swung away empty and tumbling, and what was left was the little round room, two tigers in it, and the silver shield under the floor.

"shield first," said daddy tiger, and turned them over. then earth's air caught them, and the window filled up with fire. pink, then orange, then white. sparks streamed past. the radio went to crackle, and then to nothing at all.

zephyr tiger was heavy in his seat, heavier than he had ever been, and he held daddy tiger's paw with both of his. the fire thinned. the white went blue. and mommy tiger's voice came back. "i see you," she said. "i can see you."

bang. a little striped parachute popped out above them, no bigger than a bed sheet. then bang, bang, bang: three big orange and white parachutes opened together, and the falling turned into swinging, slow and gentle, like the rope swing at home.

then the sea came up at them, blue and wrinkled and enormous, and they hit it. whump. the window went green and bubbly, and then it came up again, and they were bobbing. the whole ocean, holding them up.

daddy tiger pulled the lever and the hatch swung open, and air came in. real air. warm and wet and salty, with a gull shouting somewhere in it. zephyr tiger took his helmet off and breathed it in with his whole chest. a boat was coming.

the boat took them in to the dock, and there they were: mommy tiger with her notebook still under one arm, and auggie tiger on her hip, kicking both feet. one foot had a sock on it. one foot did not.

zephyr tiger took the little striped sock out of his pocket. it had been to the sun and back. he pulled it onto auggie tiger's bare foot, little hole and all. auggie tiger laughed and kicked it half off again.

that night they lay in the grass in the back yard, with auggie tiger sitting up in mommy tiger's lap. "the sun," said zephyr tiger. "mercury. venus. earth. mars. the rocks. jupiter. saturn. uranus. neptune. pluto." and auggie tiger said, "pwuto."

above them the stars twinkled. they had not twinkled out there, not once. "that is our air wobbling," said zephyr tiger, to nobody in particular. daddy tiger said nothing at all, and smiled at the sky.

later the map went up on his bedroom wall, with a check beside every single drawing, and the big blue question mark still on the end with nothing after it. zephyr tiger looked at it for a while. "we will need more paper," he said.

chapter one: the seed and the countdown the rocket was already standing on the launch pad when the sun came up, so tall that zephyr tiger had to lean right back to see the top of it. white vapour poured out of vents in its sides, because the liquid oxygen inside, which the engines need to burn their fuel, was colder than a kitchen freezer. “that one is ours,” said daddy tiger.

but when it was time to climb aboard, zephyr tiger was missing. mommy tiger and daddy tiger found him on his knees in her garden, filling a small clay pot with dry soil and pressing one striped seed into the top, a seed from the big sunflower head she had dried last summer. “i am not going anywhere without this,” he said.

“what for?” said daddy tiger. zephyr tiger said that earth was only the world he happened to be born on, and that somewhere out in space there had to be a better one, and that when he found it he was going to plant his seed in it, so there would be gardens on two worlds instead of only one.

daddy tiger thought about that for a while, which is what he always did before he said something true. “i have never once seen a better world,” he said, “so i cannot tell you there is one. but i will take you out to every planet that goes round our sun, and i will tell you the honest truth about each one.”

the crew cabin at the top had four seats, and they lay back in them with their knees up. zephyr tiger thought it was a silly way to sit, until daddy tiger said that lying back spreads the push of the launch over your whole back. mommy tiger buckled baby auggie tiger in. “bah,” he said. “auggie says hurry up,” said zephyr tiger.

then daddy tiger showed him a round dial with one needle. “that is all our fuel,” he said. “getting up high uses most of it, so tanker ships will fill our tanks again, and after that the needle only goes down. we cannot carry enough to stop everywhere, so at jupiter its pull will swing us round and speed us up for almost no fuel.”

“count us down, co-pilot,” said mommy tiger, and zephyr tiger took a deep breath. “three... two... one... burn!” he shouted, and far below them all thirty-three engines of super heavy, the giant booster under their starship, tiger one, lit with a roar that shook the whole ship, and the whole family said “whoomp” together as the rocket lifted off the pad.

they went up and up until the sky outside the window turned from blue to black. then most of the booster's engines stopped, and while the last few still burned, tiger one lit its own engines and pushed itself free. “the booster has used nearly all its fuel,” said daddy tiger, “and a nearly empty tank is just extra weight, so we let it go.”

tiger one's engines pushed them the rest of the way up, while far below the booster flew itself back to the launch pad, where the tower caught it in two enormous steel arms. then their own engines stopped, everything went quiet, and zephyr tiger's arms floated up all by themselves. so did the clay pot, trailing a little cloud of garden soil behind it.

he caught it, with one paw over the striped seed, and held it tight against his chest. “are we falling?” he asked, and daddy tiger said yes, they were falling, and so was the ship, and so was the soil, all of them falling around the whole world together, going sideways so fast that they kept missing it. “that is called an orbit,” he said.

out of the round window earth was an enormous blue curve with white clouds moving slowly across it, and right along its edge lay a thin, bright blue line. “that line is all the air there is,” said mommy tiger. “every breath anybody has ever taken came out of that thin layer.”

the tanker ships came up one after another and filled tiger one to the top, and then mommy tiger said, “where first?” zephyr tiger said the biggest thing, because anybody sensible does the biggest thing first, and that was the sun. “any other ship would take years and years, and far more fuel,” said daddy tiger. “ours is quicker, and goes farther. hold on.”

chapter two: the sun has no floor the engines burned a long time to send them toward the sun, and zephyr tiger watched the fuel needle drop and asked why that used so much fuel. “because we are already in orbit around the sun, like earth, falling toward it but going sideways so fast that we keep missing it,” said daddy tiger, “so to fall in close, we have to slow down.”

then the sun looked bigger and bigger in the window, the size of a pea, then a button, and when it was the size of a coin, mommy tiger said, “sun shield,” and daddy tiger swung a wide, flat shield out between the ship and the sun, so that the whole ship was in its shadow all the way down.

the front of the sun shield got hot enough to melt a saucepan, but the cabin behind it stayed as warm as a kitchen. zephyr tiger did not believe it until daddy tiger let him put his paw on the wall, and it was cool. “the shield blocks the sunlight,” said daddy tiger, “and we stay in its shadow, where the heat cannot reach us.”

“is this a good place for my seed?” said zephyr tiger, who already had the clay pot out of its net. “it has no floor,” said daddy tiger. “it is not a rock with a fire on top. it is hot gas all the way down, thicker the deeper you go, and hottest of all in the middle, and there is nowhere to stand.”

zephyr tiger said that was a ridiculous way to build something, and daddy tiger said it was the most ordinary thing in the sky, because the sun is a star, and a star is a ball of gas so enormous that its own weight squeezes its middle. “the sun is just the closest star to us,” he said. “that is why it looks so big.”

“then what makes it shine?” said zephyr tiger, and daddy tiger pressed his two paws together hard. in the middle of a star, he said, the tiniest bits of hydrogen gas are squeezed so hard that they join and become helium, a different gas, and every time two join, a little light and heat come out. “that is where all the sun's light comes from.”

then daddy tiger said something that zephyr tiger thought about for the rest of the trip. if you put the sun and every planet and every moon and every last rock together in one enormous pile, nearly the whole pile would be sun. “all the rest of it,” he said, “planets, moons, us, is only crumbs around the edge.”

mommy tiger pointed the camera past the shield, and on the screen dark patches moved across the sun, which zephyr tiger said looked like holes. “those are sunspots,” said mommy tiger, “cooler than the rest of the sun, but still hotter than anything you have stood near.” then a huge loop of glowing gas rose from the sun's edge, and the radio crackled and hissed.

zephyr tiger wanted to know how long that light took to reach home. “about eight minutes,” said daddy tiger. “so when you are lying in the grass and the sun feels warm on your face, that light left the sun eight minutes before it reached you, and crossed all this empty space on the way.” auggie tiger slept through the entire sun.

“and here is the part that matters to you,” said daddy tiger, tapping the clay pot with one claw. “a plant builds itself mostly out of air and water, and it uses the energy in sunlight to do it. every green leaf in mommy tiger's garden was made that way.” then mommy tiger turned the ship away from the sun, and zephyr tiger said, “mercury.”

chapter three: the night side of mercury mercury came up small and grey and so covered in craters that they overlapped, round holes left by rocks from space that crashed into it. “the smallest planet that goes round our sun,” said mommy tiger, lining the ship up carefully. “and we are landing on the night side.” zephyr tiger wanted to know why anybody would waste a whole planet's sunshine.

“because the sunny side is hot enough to melt lead, the soft grey metal in fishing weights,” said daddy tiger, “and our ship would have to stand on that ground.” the night side went the other way, he said, colder than any freezer at home, so cold that the ship would have to run its heaters the whole time to keep everything inside it warm.

then the whole ship went down, with everybody strapped in, and mommy tiger turned it round to come down tail first and swung its legs out. “where do the parachutes go?” asked zephyr tiger. “tiger one has none,” said daddy tiger. “it lands on its engines everywhere. and mercury has no air, and a parachute with no air is only a bedsheet.”

“count us down, co-pilot,” said mommy tiger, and zephyr tiger said, “three... two... one... burn,” and they all said “whoomp.” the big engines slowed their fall, and near the ground, small landing engines round the ship's middle took over, so the blast hit the ground more gently, and grey dust shot sideways in straight lines, because there was no air to swirl it into clouds.

then mommy tiger stopped the engines, and everything went quiet. daddy tiger sealed the clay pot inside a clear airtight box, because a seed needs air to grow, just as a cub needs it to breathe. zephyr tiger clipped the box to his suit, and the two of them rode the elevator slowly down onto grey powder that no foot had ever touched.

he turned slowly all the way round. there were craters inside craters, grey on grey, as far as the lamps could reach, and overhead the black sky was full of steady stars, because it takes air to make stars twinkle, and here there was none. “it is a rock,” he said, in the flat voice of a cub who had been hoping for a planet.

so daddy tiger walked him over to the rim of a deep crater near mercury's north pole and aimed a lamp down into it, and far down at the bottom, where the crater walls shade the floor so the sunlight never reaches it, something shone back white at them. “that is ice,” said daddy tiger. “frozen water. here.”

zephyr tiger had the clear box up in both paws before daddy tiger finished. “is this a good place for my seed?” “it is always dark down there, and a plant needs light to grow,” said daddy tiger kindly, “and that ice is as hard as the rock it sits in, and up here there is no air at all.”

as they lifted off, mommy tiger told them that mercury goes round the sun faster than any other planet, so its year, one whole trip round the sun, is only about as long as one summer at home. zephyr tiger counted on his claws and said a cub here would get four birthdays. auggie tiger said, “bah.” “auggie says four cakes,” said zephyr tiger.

chapter four: the heavy air of venus venus came up smooth and white and perfectly round, with no craters showing anywhere, because thick cloud covers the whole planet and hides the ground underneath it. zephyr tiger pressed both paws flat on the window. “that one,” he said. “that is the one. look how soft it is.”

mommy tiger said, “hm,” which from mommy tiger meant a great deal. she said venus spins the opposite way from earth, and so slowly that one whole turn takes longer than one whole trip around the sun. “and it is the hottest planet that goes round our sun,” said daddy tiger. “the clouds are the pretty part.”

they went in anyway, because daddy tiger said a careful pilot may skim the top of the air. mommy tiger folded the solar panels, which make electricity from sunlight, and turned the ship so its black heat tiles, made to take the heat, met the air first. for a while nothing happened. then the warming steel began to tick, like a pan on the stove.

the ticking grew quicker, and the smooth tops of the clouds slid by far underneath them, very fast. zephyr tiger asked whether they could open the hatch and grab a handful of cloud. “those clouds would burn you,” said daddy tiger. “they are not made of water. they are made of drops of sulfuric acid, a liquid strong enough to eat holes in metal.”

there was a second dial beside the fuel dial, and its needle sat right down at the bottom. “that shows the air pressure, how hard the air outside is pushing,” said mommy tiger. daddy tiger said that deep in the clouds the needle would point just where it points in mommy tiger's garden, and zephyr tiger shouted that they should go down there and see.

“that is the only height on the whole planet where the air pushes just as hard as it does at home,” said daddy tiger, “and it is still hot enough there to cook an egg.” deeper than that, the needle would only climb. “how far down does the pushing go?” asked zephyr tiger, and daddy tiger said, quietly, all the way to the ground.

the ticking got louder, and behind the wall a panel banged, and a warning lamp turned orange because the outside of the ship was getting too hot. “down at the bottom,” said daddy tiger, in the quiet voice he kept for careful moments, “that air is as heavy as the sea more than half a mile down. it would crush us like a paper cup.”

“up,” said mommy tiger. “now.” zephyr tiger counted faster than he had ever counted in his life, three two one burn, and the engines shoved them hard, and the ship climbed up out of the air while the clouds dropped away below, and the ticking slowed and stopped, and they were back in the quiet black with their hearts pounding.

“is this a good place for my seed?” zephyr tiger asked, once his voice came back, and he already knew the answer. daddy tiger said the heat would have charred it black before it reached the ground. so zephyr tiger held the clear box between his knees with both paws round it and said nothing for a while, which was not like him at all.

chapter five: the blue one on the way back out, a blue world came up in the window, and zephyr tiger asked which planet that was. “that one is ours,” said mommy tiger. he looked again and still could not find home in it, because from this far away you cannot see gardens or fences or gates. there was only blue, swirled with white.

they watched earth turn for a long time. the blue slid along under white spirals of cloud, which are storms, and the brown edge of a continent, one of earth's great pieces of land, came round into view, and then more ocean, and more ocean, and more ocean, until zephyr tiger said that there was an awful lot of water on their planet.

“all that blue is water,” said daddy tiger. “oceans of it, lying open under the sky.” then he said the thing that made zephyr tiger sit up: of all the worlds anybody has ever looked at, earth is the only one with liquid water out on its surface, where you could swim in it.

zephyr tiger saw the thin bright line from the first day, still lying along the edge of the world, as thin as a hair from out here. “that is the atmosphere,” said daddy tiger, “all the air earth has, and it is the only air anybody has ever found that a tiger can breathe, because it has enough oxygen, the part of air we need.”

so zephyr tiger counted on his claws the things a world has to have before a tiger could live there: solid ground to stand on, warmth, water you can drink, and air you can breathe. earth had all four. he thought about that for a moment, frowning. then he said, “but we already have that one. it does not count.”

daddy tiger did not argue with him. he said, “all right,” and he meant it. mommy tiger kept the ship going and did not slow down, because they had set out to visit every planet that goes round the sun, and that was what they were doing. earth got smaller and smaller behind them, and zephyr tiger watched it go.

“where does the road go next?” said zephyr tiger, and daddy tiger said road was a good word for it, because every planet goes round the sun in the same direction, and nearly all of them on one flat level, like runners going round one track. “so we hardly ever have to climb up or dive down,” he said. “and the moon is first.”

chapter six: footprints that stay the moon has no air, just like mercury, so tiger one came down on its engines alone while zephyr tiger counted, and the grey dust shot away sideways in straight lines, the same as before. then the legs touched, the engines shut off, and it was so quiet that he could hear his own breathing.

at the foot of the elevator, the ground turned out to be soft grey powder that his boot sank into a little way, and when he lifted his foot again the print stayed behind exactly as he had left it, with every ridge from the sole of his boot still in it, as sharp as a shape pressed into wet clay.

then he found out how light you are on the moon, because it pulls on you about a sixth as hard as earth does. he bent his knees and pushed, and went up, and up, and kept going up, and came down again slowly, laughing the whole way. he had jumped higher than daddy tiger can jump at home, and daddy tiger said so.

overhead the sky was black, not the dark blue of evening but black as midnight, in the middle of the day, with the bright sun on his shoulder, because the moon has no air to spread the sunlight across the sky. he shouted as loud as he could and heard it only inside his own helmet, because there was no air outside to carry it.

and up in all that black was earth, blue and small, and the strange part was that it stayed in one place. it did not rise and it did not set. daddy tiger said it would still be in that same spot above the hills all week, because the moon always keeps the same side turned towards earth.

“and this moon,” said daddy tiger, tapping the ground with his boot, “pulls on our sea.” zephyr tiger said that was backwards, because the sea is enormous and the moon is much smaller than earth, so daddy tiger explained how the moon's pull draws the sea up the beach and lets it fall back, twice a day, and that is called the tide.

zephyr tiger knelt down and dug with both paws, looking for something better underneath, and found only more of the same: grey powder as far down as he could dig, dry as chalk and gritty as sand, with tiny sharp grains that clung all over his gloves. “it is not soil,” said daddy tiger. “it is rock, smashed into powder by rocks falling from space.”

he set the clear box on the ground anyway and asked, “is this a good place for my seed?” “the powder has no water that roots could drink,” said daddy tiger, “and no air, and the ground gets hotter than boiling water by day and colder than any winter on earth at night. i am sorry. this one is beautiful, but not for seeds.”

but then daddy tiger said there was one fine thing about a world with no wind and no rain. he walked zephyr tiger far from the ship, where its engine blast could not reach, and they pressed their boots into the powder side by side. “those will still be here when you are old,” he said, “because nothing out here can blow them away.”

as they lifted off, zephyr tiger kept his face at the round window and watched the two prints get smaller, the big one and the small one side by side in all that grey, until he could not pick them out from the craters any more. “they are still there,” he said, to nobody in particular. “they are still there right now.”

chapter seven: the rusty planet mars came up red, and it really was red, the orange-red of a clay flowerpot. “why?” said zephyr tiger, and daddy tiger said the dust on mars has rust in it, the very same rust an old iron nail gets when it is left out in the rain, and there is enough of that dust to cover the whole planet.

mars needed something the moon did not. “mars has air, just about,” said daddy tiger, and he handed zephyr tiger a spare heat tile, black and six-sided. “that air is more than a hundred times thinner than ours, but we come in so fast that it gets very hot, so we fall belly-first, and thousands of these tiles take the heat.”

so tiger one came down in three steps. first it fell belly-first, the black tiles glowing orange while the flaps steered by pushing on the air. then mommy tiger said, “flip,” and the ship swung upright, tail down, as the engines lit. last the legs touched the ground, and the dust rolled away in clouds, because here there was air to carry it.

outside, everything was red: red ground, red stones, red dust piled up against the stones. and the sky was a different colour too, not blue but a dusty pink, because fine red dust floats in the air. the sun hung in the middle of that pink sky, smaller than the sun he knew at home, and paler, because mars is farther from the sun.

“can i try just one breath?” said zephyr tiger, which is the sort of thing you only ask once. “no,” said daddy tiger, straight out. “there is air here, but it is far too thin, and nearly all of it is carbon dioxide, the gas you breathe out. outside the ship, your helmet stays on, everywhere, the whole trip.”

they flew tiger one to two things so big that up close you could hardly tell what they were. the first was olympus mons, the biggest volcano anybody has ever found, so wide and gently sloped that from below it looked like ground going up, farther than a week's walk. it was two and a half times as tall as the tallest mountain at home.

the second was a canyon called valles marineris. it started right underneath them and kept going, far past anything they could see, deeper than any canyon at home and long enough to stretch across a whole country. “does it go all the way round mars?” said zephyr tiger, and daddy tiger said about a fifth of the way round, which is quite far enough.

a day on mars is almost exactly as long as a day at home, only about forty minutes longer, which zephyr tiger announced was the best fact of the entire trip, because forty extra minutes is forty extra minutes. then daddy tiger looked out at the horizon, the line where the ground meets the sky, and stopped smiling.

the dust storm came toward them like a wall the colour of weak tea, moving slowly and steadily. they got inside, and daddy tiger pulled the hatch shut and latched it, and then the whole ship began to hiss softly all over, because the wind was blowing fine dust against its steel sides.

they sat in there with the lamps turned down low, and zephyr tiger asked how big the storm was. “one of these can cover the whole planet,” said daddy tiger. “every bit of it, top to bottom, for weeks.” and he said it in such an ordinary voice, holding the cub's paw in his, that zephyr tiger was hardly frightened at all.

when the storm finally passed, everything was covered in fresh dust, and in the morning there was white frost on the stones, made of real frozen water, as thin as the mist your breath makes on a cold window. zephyr tiger got the clear box out slowly, because he had been saving this one up. “is this a good place for my seed?”

daddy tiger took a while to answer. “there is water here, and sunlight, and ground,” he said, “and it is still no. the air is too thin, with almost no oxygen for a seed, and one night of this cold would kill a young plant. but people are working on greenhouses for mars that hold our own warmth and air, so one day, maybe.”

and zephyr tiger looked down into the clear box, at the small clay pot and the plain brown soil he had dug out of mommy tiger's garden with his own two paws and carried all this way. he put one glove flat on the lid of the box and kept it there. daddy tiger saw, and let him be.

chapter eight: phobos and deimos once tiger one had climbed back up off mars, they went to see the two moons of mars, phobos and deimos, which are both small and not round at all. “potatoes,” said zephyr tiger when he saw the first one, because it really was the shape of a potato, and after that the whole family called them the potatoes, even mommy tiger.

“why are they lumpy?” he asked. daddy tiger said that a world gets pulled round into a ball by its own gravity, the pull that everything has. the bigger a thing is, the harder it pulls, and these two are too small to pull themselves round. “anything big enough ends up round,” he said. “anything small stays whatever shape it broke in.”

they came close enough to phobos to see it properly: grey, covered in craters, and scratched all over with long straight grooves. one crater, called stickney, was so wide that it reached almost halfway across the moon, as if a piece had been cut out of one end. the whole moon was about as wide across as a city.

“phobos goes right round mars in under eight hours,” said mommy tiger, and zephyr tiger went very still. he looked at phobos, and then down at mars turning slowly underneath it, and then back up at phobos again, and everybody in the cabin could see that he was working something out.

“it goes round faster than mars turns,” he said. “so if you stood down there, it would catch you up and go past you, and it would come up in the west, where the sun goes down, and it would do it twice in one day!” and daddy tiger said, “that is exactly right,” and he was not pretending.

deimos was smaller still, a dark lump about half as wide as phobos and farther out. zephyr tiger did not get the clear box out. “you cannot grow a garden on a potato,” he said, and daddy tiger laughed. “you can grow a row of potatoes from one potato,” he said, “but not from that one.” then mommy tiger turned them toward the asteroid belt.

chapter nine: the belt is mostly nothing zephyr tiger put his helmet on for the asteroid belt, a wide ring of rocks called asteroids that go round the sun between mars and jupiter. he strapped himself in, held the edges of his seat with both paws, and stared out of the window, ready for the rocks to come flying at them the way they do in his game at home.

nothing came. nothing came for a very long time. then, hours later, something did come: one grey rock, about the size of a hill, sliding past so far away that it looked smaller than his own claw. and after that, nothing again, for hours and hours more.

“there are millions of asteroids out here,” said daddy tiger, “but there is so much room in between them that the belt is nearly all empty. you could fly right across it with your eyes shut and almost never hit one. if you really want to hit a rock out here, you have to aim at it.”

zephyr tiger took his helmet right off and said that the belt was the most disappointing thing that had ever happened to him. mommy tiger said she would make a note of it. and then, somewhere out in all that empty space, a world came into view against the black, and it was round.

“that is ceres,” said mommy tiger, “and it is a dwarf planet.” zephyr tiger asked if that meant small or pretend. “it is small, but it is real,” said daddy tiger. “it is heavy enough to pull itself round into a ball, but a planet has its part of space round the sun to itself, and ceres shares its part with millions of asteroids.”

ceres was dark grey all over except for a few places down inside one wide crater that were so white they shone like a flashlight beam on a wall. “that is salt,” said daddy tiger. “salty water came up from deep inside ceres, and when the water turned to vapour and drifted off into space, the salt was left lying in the open.”

landing was the easiest one yet, because ceres pulls so weakly. the engines only had to fire for a few minutes to slow them down, and they settled so gently that the legs hardly pressed into the dust. then daddy tiger drove a thin anchor into the rock to hold tiger one steady, just in case, while they were walking on it.

then zephyr tiger jumped, out of habit, the way he had jumped on the moon. he went up past the ship's legs. he went up higher than the roof of his house. he hung about up there for a while, turning slowly, with a great deal of time to think about it, and he came down so slowly that he got bored before he landed.

daddy tiger told him that there is water ice on ceres, frozen hard in the dusty ground. “is this a good place for my seed?” said zephyr tiger, from flat on his back. “no,” said daddy tiger. “there is no air here, and this far out the sun gives so little heat that even the warmest ground is colder than the freezer at home.”

back aboard, mommy tiger tapped the fuel dial, and zephyr tiger saw that the needle had slid down past halfway. “and we still have the whole way out,” she said, “and the whole way back.” daddy tiger looked out at the bright dot of jupiter far ahead and said that jupiter's pull would have to give them the push they needed.

chapter ten: the push from jupiter jupiter did not come up like the others. it came up, and then it kept coming up, and then it went on coming up until it was not a thing in the window any more but filled the whole window from edge to edge. it is so big that every other planet put together would fit inside it, with room left over.

it was striped in wide bands of cream and rust and pale brown cloud, and the bands slid past each other at different speeds, because the wind blows east in some bands and west in others. and it was turning fast. the whole enormous planet turns right round in about ten hours, a shorter day than any other planet has.

then the great red spot came round the edge, one red-brown oval of cloud turning slowly round and round, and it was a storm a little wider than the whole of earth. “that storm has been going for nearly two hundred years,” said daddy tiger, “longer than anybody's grandpa has been alive. and it is still going, though it is slowly getting smaller.”

“so where do we land?” said zephyr tiger, and then answered himself before anybody else could. “oh,” he said. “there is nothing to land on, is there.” “like the sun,” said daddy tiger. “no ground the whole way down, just gas getting thicker and hotter the deeper you go, until it is squeezed into a hot liquid. but jupiter is cold on top.”

jupiter has more than a hundred moons, which zephyr tiger said could not possibly be true, and mommy tiger said that people keep on finding more of them with their telescopes, so the number goes up every few years. zephyr tiger said that having a hundred moons was greedy. auggie tiger said, “bah.” “auggie says he wants one,” said zephyr tiger.

then mommy tiger told them what she had been working out on her pad all morning. “we do not have enough fuel to get out past jupiter,” she said. “not to saturn, and nowhere close to pluto. not if we use the engines to get there.” zephyr tiger looked at the fuel dial, and at the needle, and then up at daddy tiger.

“and that is exactly why we came this way,” said daddy tiger. “first we visit its moons. then, when we leave, we fly in close and give one short burn, and jupiter's pull throws us out faster than the burn alone could. the extra speed comes from jupiter's own movement round the sun, but jupiter is so heavy that it hardly changes at all.”

“but close in is where the push is,” said mommy tiger, “and close in is also where the radiation round jupiter is strongest, a kind of energy you cannot see or feel that can make people very ill.” so they worked out the numbers together for a while, which zephyr tiger thoroughly enjoyed, and chose a path that went near enough and no nearer.

it was the fastest thing that had ever happened to him. jupiter came up underneath them until there was nothing else anywhere, the cloud stripes rushing past, the great red spot going by below, and the speed on mommy tiger's screen going up and up and up, while the fuel needle stayed exactly where it was and did not move.

then, at the lowest point, mommy tiger said, “count us down, co-pilot,” and zephyr tiger said, “three... two... one... burn,” and they all said “whoomp.” that short burn used a little fuel and slowed them down just enough for jupiter's pull to hold them in an orbit, going round and round it. “the big throw comes later,” said daddy tiger, “on the way out.”

chapter eleven: the moon of volcanoes and the moon of ice going round jupiter, they came to its big moons one at a time, and io came first. io did not look like any moon zephyr tiger had ever seen. it was yellow and orange and white and pale green, all in patches, because its volcanoes coat the ground with sulfur, a yellow mineral, and with white frost made of a volcano gas called sulfur dioxide.

while they were watching, a pale fountain of gas and dust rose off the ground near its edge, straight up and enormously high, and spread out at the top like an umbrella, and fell back down again. it made no sound at all, because io has almost no air, and without air there is nothing to carry the sound of the bang.

“io has about four hundred volcanoes that still erupt,” said daddy tiger, “and more of them erupt at once than anywhere else in the solar system, which means the sun and everything that goes round it. most are wide, flat pits, not mountains. jupiter's pull squeezes io over and over, and all that squeezing heats the rock inside until it melts.”

mommy tiger kept them high above all of it. “of all jupiter's big moons, io gets the most radiation, those rays we cannot see or feel,” she said, and she did not stay long, and daddy tiger agreed with her out loud, which zephyr tiger noticed, because when grown-ups agree out loud about something, it usually matters.

europa was nothing like io. it was white, and it was smooth, the smoothest ground of any world in the solar system, with hardly a crater on it, and all across the white ran long reddish-brown cracks, like the cracks in a frozen puddle after somebody has stepped on it.

“ice,” said daddy tiger. “the whole outside of it is ice, and that ice is miles deep, deeper than the tallest mountain on earth is high, so if you landed on it and started digging down, you would still be digging when you were as old as me.”

“and underneath the ice,” he said, “there is water. real liquid water, salty like the sea, a whole ocean of it, many miles deep. there is about twice as much water down there as there is in all the seas on earth put together.”

zephyr tiger shot upright so fast that he banged his head on a locker. “fish,” he said. “daddy tiger. there are fish.” and he was completely sure of it, the way anybody is sure of something enormous in the first minute after they have thought of it, before they have had time to ask any questions.

daddy tiger did not say yes and he did not say no. he said nobody has ever found one living thing anywhere but earth, not a fish, not a leaf, not even a germ, and nobody knows what is under that ice. “i will not say yes just to make you happy,” he said, “and i will not say no when i don't know.”

“is this a good place for my seed?” said zephyr tiger, quietly, already knowing. “under miles of ice, where no sunlight ever reaches? no.” and then daddy tiger said the other true thing: people have sent ships out to look at europa, and one day somebody may find out what is down there. “it might turn out to be somebody who is four right now.”

chapter twelve: the biggest moon of all ganymede is the biggest moon in the solar system, and it is wider across than the whole planet mercury, which zephyr tiger said was plainly against the rules. “whose rules?” said mommy tiger. he could not think of anybody's rules exactly, so in the end he let it go, but he did not like it.

and ganymede has one thing that no other moon we know of has: its own magnetic field, the invisible pull around a magnet, made deep inside it the way earth makes one. zephyr tiger swept a bar magnet past daddy tiger's compass, and the needle swung round after it. “ganymede is a magnet like that,” said daddy tiger, “only as big as a whole moon.”

callisto, the next moon out, was pale and grey and covered all over in craters, craters on top of craters on top of craters, until there was hardly room left for another one. “that is the most cratered ground in the whole solar system,” said daddy tiger. “no wind or rain or volcano has smoothed it over for about four billion years.”

“and this,” he said, “is the one we will land on. callisto is far enough from jupiter that the radiation is weak here, and that is why we picked it.” zephyr tiger asked to land on europa too, and daddy tiger said, “no, the radiation is strong there, and i am taking you home safe.”

there is no air on callisto, so there was no belly-first fall and no glowing tiles, just the countdown and the burn, and dust flying out flat and straight, and then the legs touching down. zephyr tiger had watched so many landings that he called out each step before it happened, and mommy tiger laughed and said soon he could land it himself.

outside, jupiter hung in the black sky above him, striped and enormous, about eight times as wide as the moon ever looks from a garden at home, and the great red spot moved slowly round its side as jupiter turned. he stood and looked up at it for a long while and did not say one single word.

then he did something nobody had asked him to do. out where the ship's blast could not reach, he stacked flat stones one on top of another until the pile stood higher than his helmet, and patted the top one down. it was a cairn, a pile of stones that people build to mark a place. “so somebody knows we were here,” he said.

he did not even ask about the seed this time. he got the clear box out, held it up, looked at the grey ground and the black sky and his stones, and put it away again. “i know,” he said, before daddy tiger could speak. “there is no air and no soil, and it is much too cold.” “much too cold,” agreed daddy tiger.

on the way up, zephyr tiger watched his cairn until it was gone, and the fuel needle dropped, because landing and leaving cost fuel. then mommy tiger flew them close to jupiter and gave one short burn, and jupiter's pull swung them round and sent them out into the dark faster than any tiger has ever gone, just as daddy tiger had said it would.

chapter thirteen: the rings and the fountain nobody had to tell zephyr tiger to look. saturn came up out of the dark with its rings lying flat and wide all around it, pale gold and perfectly still, and he stopped talking. he stopped talking for four whole minutes, which mommy tiger said afterwards was the real discovery of the trip.

and it was not one ring. the closer they came, the more rings they could see: rings inside rings inside rings, thousands of them laid side by side, with thin dark gaps between them, and through the gaps they could see straight out to the stars on the other side.

“how thick are they?” said zephyr tiger, and daddy tiger said that was the best question anybody had asked all week. the rings are so wide that more than twenty earths in a row would fit across them, but in most places they are only as thick as a house is tall, so from the side they very nearly disappear.

there is a gap between saturn and the ring closest to it, and mommy tiger flew them straight through it. “count us down, co-pilot,” she said, and zephyr tiger said, “three... two... one... burn.” “whoomp,” said everybody, and the rings went over their heads in one thin bright line, like a bridge, and saturn's clouds went by under their feet like a floor.

and that was when he saw what the rings really are. they are not a sheet or a ribbon or one solid thing at all, but pieces: billions and billions of separate pieces going round saturn together, specks as fine as dust, snowballs, lumps the size of a house, a few as big as a hill, and nearly all of them ice.

daddy tiger went outside on a safety line and brought in a chunk, and zephyr tiger held it in his paws. “could we make fuel from it?” he asked. “some of it,” said daddy tiger. “this ice is nearly all water, and that gives oxygen, but not the rest of our fuel. and with our trickle of electricity, it would take months of sitting still.”

“and here is a strange thing about saturn,” said daddy tiger. “it is made mostly of gas, so it is very light for how big it is, and if you had a bath big enough to put it in, it would float.” zephyr tiger spent some time after that imagining the bath, and then the bathroom, and then the house.

then they flew over the top of saturn, and around its north pole was a storm with six straight sides, like one cell of a honeycomb, more than twice as wide as earth, turning slowly. “why six?” said zephyr tiger. “the winds blow round in that shape,” said daddy tiger, “and nobody knows exactly why. it has been six-sided as long as we have looked.”

saturn has a small white moon called enceladus, and as they came round it, they flew past tall jets of ice and water vapour, which is water turned into a gas. the jets shot up out of cracks near its south pole, spread out at the top like feathers and reached far out into space, glittering wherever the sun caught them.

“it has a whole ocean of liquid water under its ice,” said daddy tiger, “and the water sprays out through the cracks. and the cracks have a name.” he looked at zephyr tiger for a moment, enjoying himself thoroughly. “they are called the tiger stripes.” zephyr tiger made a sound that was mostly just air.

that spray, daddy tiger said, is what one of saturn's rings is made of, so this small moon is adding ice to a ring all the time. “is this a good place for my seed?” asked zephyr tiger hopefully, holding up the box. “the water stays water for only a moment,” said daddy tiger, “and then it freezes into snow. no.”

chapter fourteen: rain that is not water titan, the biggest of saturn's moons, has air, and so much of it that you cannot see the ground, because the air is full of thick orange haze, a kind of smog. from above it was a smooth orange ball, the colour of a tangerine, and zephyr tiger kept asking where the actual moon was, because all there was to look at was weather.

this one needed the heat tiles again. tiger one came in belly-first, its solar panels folded away and its black tiles glowing, and the thick air slowed it down, so it fell for a long, long time with the flaps steering. zephyr tiger had time to count every bolt on the walls. then, still high up, mommy tiger flipped it upright and lit the engines.

and then the haze thinned out, and underneath it was a real shore, with rivers running down to it in branches and a wide flat lake lying there dark and still, and zephyr tiger shouted that from up here it looked just like home. it did look like home, but it was nothing like home at all.

they came down on a beach of pale grit under an orange sky, with orange light and orange shadows and every single thing the colour of a jar of marmalade, and the lake in front of them lay so flat and so black that it looked more like a hole in the ground than a lake.

“that is not water,” said daddy tiger. “it is mostly liquid methane, the same gas that comes hissing out of the stove at home when you turn it on. only out here it is so cold that the gas turns into a liquid and pours.” zephyr tiger said that was the strangest thing anybody had said all trip, and he had been keeping track.

then it rained on them. the drops were methane, like the lake, and they were bigger than raindrops at home and fell much more slowly, because the air is so thick and titan pulls on things so weakly. when zephyr tiger held out a glove to catch one, he could follow it all the way down with his eyes.

zephyr tiger kicked a boulder, just to see, and hurt his foot, so daddy tiger rubbed the sore boot. “that boulder is water ice,” he said. “out here it is so cold that the ice never melts, and it is as hard as stone. you could build a garden wall out of it.”

“and one more thing about this place,” said daddy tiger. “the air here is so thick, and this moon pulls on you so weakly, that a person with big enough wings could really flap them and fly.” zephyr tiger grabbed two sheets of foil, flapped as hard as he possibly could, and got one hop. “bigger wings,” said daddy tiger, smiling.

“is this a good place for my seed?” asked zephyr tiger, dripping with the wrong sort of rain. “no,” said daddy tiger. “it is far too cold, and the rain is methane, and all the water on the ground is frozen solid.” zephyr tiger nodded, clipped the box back onto his suit, and they climbed up out of the orange.

chapter fifteen: the planet on its side it took a long time to fly out to the next planet, and all that time the sun looked smaller and smaller, until it looked like the brightest star in the sky. daddy tiger folded the solar panels flat against the steel back of the ship, because out there sunlight is hundreds of times weaker than at home, too weak to make much electricity.

“so what runs the lights now?” said zephyr tiger. daddy tiger showed him a grey box on a metal arm outside. “that is a radioisotope generator, a kind of nuclear battery,” he said. “the material inside stays hot all the time, and the box turns that heat into electricity. it needs no sun, and it will still be working when you are grown up.”

when they finally reached uranus, it was a smooth, pale blue-green ball with hardly a mark anywhere on it, the colour of a swimming pool. “why that colour?” said zephyr tiger. “its air has methane in it, like titan's,” said daddy tiger, “and methane soaks up the red part of sunlight, so the light that bounces back to us is blue-green.”

and uranus is tipped right over on its side. every other planet spins more or less upright, like a top standing on a table, but uranus spins on its side, so as it goes round the sun, it turns over and over like a ball rolling along a lane.

“that makes summer and winter very strange there,” said mommy tiger. “the north pole, at one end of the planet, has sunshine for about forty-two years without a break, and then the sun goes down, and it does not come back up for another forty-two years.” zephyr tiger said that if he lived there, he would be an old man before breakfast.

uranus has rings too, but they are thin, dark and narrow instead of bright and wide like saturn's, and because the planet is tipped on its side, its rings stand up around it like a ferris wheel. one of its small moons, miranda, has a cliff so tall that it is probably the tallest cliff in the whole solar system.

“but why is it tipped over?” said zephyr tiger, which was the question he most wanted answered on the whole trip. daddy tiger said that scientists think something as big as earth crashed into it a very long time ago and knocked it over. “but nobody knows for certain yet,” he said, “and that is the best kind of question there is.”

uranus also has the coldest air of any planet, though daddy tiger said that a couple of small icy worlds further out have air that is colder still. and uranus is not even the farthest planet, which zephyr tiger thought was rather unfair on the farthest one.

“is this a good place for my seed?” said zephyr tiger, because he always asked. “there is no ground to stand on, and no warmth, and hardly any light,” said daddy tiger, “but i am proud of you for asking.” so mommy tiger used the pull of uranus to swing the ship round, the way they had at jupiter, and they flew on toward neptune.

chapter sixteen: the windiest place there is it was dark out there in a way zephyr tiger had no word for. the sun was a hard white point, far too small to look like the sun, and even where it shone full on the ship it was only as bright as the last ten minutes of an evening at home, after the lamps go on but before anybody says bedtime.

neptune came up pale blue, a little bluer than uranus had been, with a few long white streaks of cloud stretched out across it. it was the last planet. after this one, daddy tiger said, there are no more planets at all, only a wide belt of small frozen worlds made of ice and rock.

and it is the windiest place in the whole solar system. those white streaks were clouds blown along faster than the big passenger planes at home can fly, hour after hour, right round the planet. “at home, the sun's heat drives the wind,” said daddy tiger, “but out here there is hardly any sunlight, so nobody is sure yet what drives these winds so hard.”

then mommy tiger told him how neptune was found, and it was the most amazing thing he had heard yet. uranus, she said, kept turning up in slightly the wrong place, as if something heavy were pulling on it, so a scientist sat down with a pencil and paper, worked out roughly where that heavy thing had to be, and said, look there.

“and it was there?” said zephyr tiger. “the first night they looked,” said mommy tiger. zephyr tiger thought about that for a long while. “so you can find a planet,” he said slowly, “by thinking about it.” “that is exactly what happened,” she said, and he went very quiet and looked down at his own paws.

neptune has a big moon called triton, and triton goes round neptune backwards, the opposite way to neptune's spin. “nearly everything out here goes round the same way,” said daddy tiger, “but that one does not, so scientists think it did not start out here but came from further out, and neptune's gravity, the pull that every heavy thing has, caught it and kept it.”

and triton has geysers, which shoot up like fountains, only these are freezing cold: dark plumes of gas and dust going straight up off the pinkish ice and bending right over at the top, where a wind nobody had expected blows them sideways. “ice volcanoes,” said daddy tiger, and zephyr tiger said those two words should not be allowed to go together like that.

“is this a good place for my seed?” said zephyr tiger. “no,” said daddy tiger, “because neptune has no solid ground at all, and triton is even colder than the air on uranus, and that was the coldest air of any planet.” zephyr tiger put the box away without any fuss at all, because he had something else on his mind now.

“what is next?” he said. “pluto,” said daddy tiger, “and pluto is a dwarf planet, the way ceres was. i wanted you to hear that from me, before somebody else says it as though it means pluto is not good enough, because that is not true, and pluto is worth the whole trip.”

chapter seventeen: the small cold heart zephyr tiger arrived at pluto cross, and he was cross for pluto, not for himself. “why is it not a planet?” “it is round, which is the hard part,” said daddy tiger, “but it shares its orbit, its path round the sun, with hundreds of other icy things, and a planet has its path all to itself. that is the only reason.”

“and it is small,” said daddy tiger, “smaller than our own moon, only about two thirds as wide. you could set pluto down on top of the moon and still have moon left over all the way round the edge.” zephyr tiger said that was a mean thing to say about pluto, and daddy tiger said it was not mean, it was only true.

and then pluto came up, and zephyr tiger forgot every single thing he had been cross about. it was pale brown and cream and grey, and across the front of it, enormous and pale and very nearly the right way up, was a heart, a wide stretch of ground shaped just like a heart, right there on pluto, facing them.

“is it painted on?” he said. “no, the left half is a glacier, a wide field of ice that moves very slowly,” said daddy tiger. “it is frozen nitrogen, the gas that makes up most of the air we breathe, lying in a hollow hundreds of miles across, and it slowly turns over in circles, the way porridge does when it heats in a pan.”

it was a slow, gentle landing. pluto has air, but it is mostly nitrogen with no oxygen to breathe, and far too thin for the tiles and flaps to help, so the engines did all the work of slowing them down, and high above them that thin air was stacked in layers of blue haze, which is the last colour anybody expects out there.

the mountains were water ice instead of rock, miles high and sharp-edged, and as hard as the ice boulder on titan. the sun was a tiny white point, too bright to look straight at but bright enough to make a shadow, and because it was low in the sky, his shadow stretched far across the ice.

then they flew tiger one over to the side of pluto that faces charon, and there it was, a grey moon half as wide as pluto, a very big moon for such a small world. “those two go round each other,” said daddy tiger, “round a point in the space between them, the way two people swing round when they hold hands and lean back.”

and then zephyr tiger said, slowly, “it is not moving.” he watched it a while longer. “it is not going anywhere at all. it is just hanging there.” and then his whole face changed. “like earth did! on the moon! it stays in one place!” “you got there before me,” said daddy tiger. “charon and pluto always keep the same side turned to each other.”

mommy tiger said one more thing over the radio: pluto takes about two hundred and fifty years to go once round the sun, so since the day people first found it out here and gave it a name, it has not gone all the way round even once. “so pluto has not had one birthday yet,” said zephyr tiger, very pleased.

“is this a good place for my seed?” he said, and he already knew, and he asked anyway, and daddy tiger told him the truth: there was nothing to breathe, no water it could drink, and it was much too cold for anything to grow. zephyr tiger looked round at the ice, and the big grey moon. “then i am taking it home,” he said.

chapter eighteen: a snowball with a tail out past pluto there was more: a whole wide ring of icy worlds going round the sun in the dark, thousands and thousands of them, every one a very long way from the next. “this is the kuiper belt,” said daddy tiger, “and pluto is one of the icy worlds in it. it is not the last thing out here at all.”

and then the needle on the fuel dial went down almost to the bottom, and mommy tiger said it straight out, the way she always did. “we cannot get home on what is left in those tanks,” she said. “we would not get a quarter of the way. so we are going to have to make some more fuel.”

and zephyr tiger, who had been thinking about it ever since saturn, said, “the ice.” everybody turned round and looked at him. “you said we could make fuel from ice,” he said. “you said it would take months of sitting still. we have got months.” “we have got months,” agreed daddy tiger, slowly.

daddy tiger told him how big the job was. comet ice is frozen water with carbon dioxide mixed in, which gives everything the engines burn, but they would need a lump bigger than a hill. “nobody has done this yet, only planned it,” he said, “and any other ship would take longer than anybody lives, but ours is quicker.” zephyr tiger said that sounded fine.

they found a comet, which people call a dirty snowball of ice and dust, but it was not much of a snowball at all. it was a dark lumpy mountain, darker than charcoal and far more dust than ice. titan had fuel too, but this comet was already falling in toward the sun and toward home, so it would carry them while the tanks filled.

landing on it was almost funny. its pull was so weak that the ship touched, bounced, went up higher than a house, came down a long way off, bounced again, and stopped. then daddy tiger fired a harpoon, an anchor on a long line, down into the dust to hold the ship there, because the smallest push would have floated it off again.

and then they waited. they melted the ice out of the dust in a pot about the size of a kettle, over and over and over again, and the nuclear battery made its slow trickle of electricity, and the tanks filled a thumb's width at a time, and zephyr tiger learned to play cards, and auggie tiger learned to clap his paws.

“so how does ice turn into fuel?” said zephyr tiger, after a great many days. “water is two gases joined together, hydrogen and oxygen,” said daddy tiger, “and if you push electricity through it, they come apart. the oxygen goes in one tank. then we join the hydrogen to the carbon dioxide, the gas you breathe out, and that makes methane for the other tank.”

and then one evening zephyr tiger looked at the fuel dial and shouted so loudly that auggie tiger cried. the needle had moved, and it had moved up! for the first time since the tanker ships filled them, it had gone the other way, and it kept on going, slowly, day after day, while the comet carried them in toward the sun.

as they came in, sunlight warmed the comet, and its ice began turning straight into gas without melting first, and a glowing cloud of gas and dust grew up all around them, and a tail came streaming out behind. “a comet's tail always points away from the sun,” said daddy tiger, “so when a comet goes back out again, its tail goes first.”

the night before they let go of the comet, zephyr tiger filled a jar with water from the melting pot, screwed the lid down tight, and put it away in the pocket of his suit. daddy tiger watched him do it and did not ask one single question about it, and zephyr tiger noticed that, and he was glad.

chapter nineteen: the long fall home they cast off from the comet with its glowing cloud of gas and dust all around them and the tail reaching away behind, and the tail got longer every single day as they came in, because the closer a comet gets to the sun, the more of its ice turns to gas and streams out. it was the biggest thing zephyr tiger had ever ridden.

on the way in, he named every place they had been, and he had earned it. “pluto and charon,” he said. “neptune and triton. uranus, on its side. saturn and the rings. enceladus and the tiger stripes. titan with the methane rain. jupiter and the swing. io, europa, ganymede, callisto. ceres. phobos and deimos. mars. the moon. venus. mercury. the sun.”

once the sunlight was strong enough to be useful, daddy tiger unfolded the solar panels again, and they opened out slowly on either side of the ship. “we will not need the radioisotope generator, our nuclear battery, any more,” he said, patting its case, and zephyr tiger patted it too, because its electricity had kept their lights on all the way through the dark.

they went by the big planets again, but far off this time, so the big ones looked small, and zephyr tiger watched jupiter go past and did not ask to stop. “i have been there,” he said, which is a thing almost nobody can say about jupiter, and he said it the way somebody puts a coin into a pocket.

then came the longest burn of the trip. to slow a ship down you turn it right round and burn the engines against the way you are going, which feels exactly as wrong as it sounds. “count us down, co-pilot,” said mommy tiger, and zephyr tiger did, and everybody said “whoomp,” and they burned backwards, on and on, falling toward home.

earth got bigger in the window until it was not a marble any more, and then not a ball, and then just blue, everywhere, with white clouds turning slowly across it, and auggie tiger put both paws flat on the glass and said “bah,” and for once nobody translated, because everybody agreed.

tiger one had landed them on eight different worlds, if you count a comet, and now it would carry them down through earth's air too, because it was built to come home whole and fly again. so daddy tiger folded the solar panels and the nuclear battery in flat, and everybody buckled in, helmets on.

then mommy tiger turned the ship round so its black belly faced the way they were going. “the heat tiles took us down through the air at mars and at titan,” said daddy tiger, “but this time we are coming in faster than ever, so this will be the hottest of all.” and he checked everybody's straps, and then he checked them again.

the thin blue line of air does not feel thin at all when you come in fast from outside. tiger one fell into it belly-first, so hard that the air under the tiles grew hotter than a furnace and roared, and the window filled with glowing pink and orange, while the flaps swung to and fro, steering, and the whole ship shook.

“it is meant to do that,” said daddy tiger over the noise, in his quiet voice. “the tiles get hot so that we do not.” then the roaring thinned out into ordinary wind, and the window went from black to deep blue to the bright blue of a daytime sky, and mommy tiger said, “flip,” and the engines lit, and the ship swung upright.

they came down slower and slower on the engines, onto a landing pad by the sea, near the tall tower they had left from all that time ago, and the legs touched, and everything went still. and when daddy tiger opened the hatch, fresh air came in, real air that moved, cool and smelling of the salty sea, and zephyr tiger took his helmet off.

chapter twenty: the only garden anyone has found the gate still squeaked when they opened it. that was the thing zephyr tiger had somehow not expected: everything at home had carried on just as usual the whole time he was away. the grass had grown long, and the garden smelled of rain and soil and warm green leaves, all at once.

he took the clay pot out of the clear box and held it up in both paws, in his own garden, in air that he could breathe. “is this a good place for my seed?” “yes,” said daddy tiger. “this is the one.”

“and here is why,” he said, crouching down. “a plant needs light, and air, and warmth, and soil for its roots, and water for those roots to take up. and you and i went and looked at every planet the sun has, and lots of moons too. this is the only place anybody has found with all five of them in the same spot.”

“not yet, though,” said daddy tiger. “a big sunflower needs a whole summer of warm days, and this summer is nearly over, so the cold would come before it flowered.” so the seed waited all winter in its pot, dry and cool on a shelf in the shed, and in the spring they dug a small hole, and zephyr tiger pushed his striped seed in.

then he brought out the jar. “this is water from the comet,” he said, “melted out of its ice. i brought it all this way.” mommy tiger asked him what he had brought it for, and zephyr tiger unscrewed the lid, and poured the comet water over his seed in his mother's garden, and said, “for this.”

“count us down, co-pilot,” said mommy tiger, which was a joke, and zephyr tiger counted anyway: “three... two... one... burn,” and they all said “whoomp,” and absolutely nothing happened at all, because a sunflower seed takes a week or so to come up, and they all knew that, and they sat and looked at the soil for a while all the same.

it came up nine days later, a thin green shoot with two small leaves. its hairy stem grew taller than zephyr tiger, and then taller than daddy tiger, and one summer morning there was a sunflower as wide as a dinner plate, its brown middle made of more than a thousand tiny flowers, and every one of those could make a striped seed.

that night daddy tiger took him out to look up, and now zephyr tiger could find the planets by himself: venus, low and bright, and mars, orange, over the shed, and jupiter and saturn. “where is pluto?” he said, and daddy tiger said that pluto is too small and too far away to see with just your eyes. “we went anyway,” said daddy tiger.

auggie tiger could walk by then, and say a few words, but he sat down in the grass by the flower and reached up and said, “bah,” just the way he used to. “he says this is the only world with flowers on it,” said zephyr tiger. and as far as anybody has ever found, in the whole of the solar system, he was right.