It was a bright, sunny morning, the kind where the light comes through the windows and warms your cheeks like a hug. Outside, the grass in the garden was still wet with dew, and every drop sparkled like a tiny diamond.

But inside the house there was something even better than the sun: the kitchen smelled of fresh warm bread, of flour, and of warm cookies.

Lily, Ziggy, Skye, and Dash were around the big wooden table, with their hands covered in dough all the way up to their elbows.

"Look at my star-shaped cookie!" said Ziggy, hopping up and down.

"Well, mine goes really fast!" laughed Dash, sliding a cookie across the table like a little race car.

Skye, calm as always, rolled the dough with her gentle fingers. And Lily, with her blue and eager eyes, pushed the rolling pin back and forth with all her might.

And it was right then that something strange happened.

In through the open window came... a balloon. A red balloon, round and shiny, floating in the air without making the tiniest sound. Its string dangled down like a long, thin little voice.

The four friends stared with their mouths wide open, flour still on their hands.

"A balloon!" whispered Skye. "But... where did it come from?"

The red balloon did not answer. It swayed slowly, came close to Lily's ear, and whispered, in a voice as small as a puff of wind: "In a faraway cave... the little ones are shivering with cold."

Lily narrowed her eyes. "Who is shivering? Which little ones? Where?"

But the balloon, all mysterious, spun around and only whispered: "Follow me... and remember to bring your heart."

Lily did not need to be told twice. She wiped her hands on her apron and said: "If somebody out there is cold, we can't stay here where it's warm and cozy. We have to help!"

And just then, from outside, came a sound they knew very well.

"CHOO CHOO! CHOO CHOO!"

It was Toby the Magic Train! He stopped in front of the door with a happy whistle, his wheels gleaming and his chimney puffing little white clouds. Toby greeted the children, as always, speaking in rhyme:

"CHOO CHOO, dear friends, I'm cheery and bright,
hop into my carriage, adventure's in sight!
I'll carry you off to a land icy-cold,
where you must be gentle, and brave, and bold!"

The children burst out laughing and hopped aboard in a hurry. The red balloon followed them, staying close to the window. Toby set off with puffs and whistles, racing up and down the green hills. Outside, the grass sparkled with dew, as if someone had spilled a whole bag of diamonds all over the meadow.

After a while, the little train slowed down in front of a white hill. "CHOO," went Toby softly, and stopped.

In front of them was a cave. But it was not a dark and scary cave, no. It was the Sparkle-Ice Cave: the walls were covered with frozen dew that glittered with a thousand blue and silver lights, as if all the stars in the sky had fallen inside. It was beautiful. But it was also freezing.

The children tiptoed inside. Their breath came out of their mouths like little clouds.

"Look over there," whispered Skye, pointing to a corner.

There, curled up, was a family of hedgehogs. A mommy hedgehog and three little hedgehogs, with their spikes all ruffled up. Their tiny teeth were chattering: brrr, brrr, they went, trembling like little leaves in the wind.

The smallest hedgehog lifted its little nose and said, in a shy little voice: "So cold... we came in here to hide, but the cave turned icy."

Dash frowned. "Icy? What does icy mean?"

"It means very, very cold, frozen like ice," Skye explained gently. "Like when you touch a cube inside your glass."

"Ohhh," said Ziggy and Dash together.

Lily knelt down beside the hedgehogs. "Don't be afraid. We are here to help you. We'll warm you up, we promise!"

But... how? The cave was empty. There were no blankets, no wool, nothing warm anywhere at all.

The red balloon floated above their heads and whispered its secret clue: "The answer is not here... it is in what you left behind in the kitchen."

Lily's eyes went wide. "The kitchen! Of course! It's full of soft, warm things: pot holders, dish towels, flour! Let's go back! Toby, take us home, quick!"

"CHOO CHOO! CHOO CHOO!" And in a flash they were back in the sweet-smelling kitchen.

"Quick," said Lily, "everyone grab something that can warm up the hedgehogs!"

And then something beautiful happened: each of the friends did their part.

Skye, with her gentle hands, gathered up the soft pot holders and the fluffy dish towels. "These are warm and cozy," she said. "Perfect for tiny little hedgehogs."

Dash, fast as the wind, in a blink gathered up all the cork stoppers from the pantry. "Corks don't let the cold get through!" he shouted. "We can use them!"

And Ziggy? Ziggy stood still for a second, and then a little light lit up in his eyes. "Aha! I have an idea!" he cried. He took a clean sock and filled it with flour that had just been warmed near the stove. "There we go: a warmer! Warm flour keeps its heat for a long time, just like a cozy pillow!"

"Ziggy, you're a genius!" said Lily.

They gathered everything into a big basket: pot holders, dish towels, cork stoppers, and the sock-warmer. And then Lily took the last thing, the most important of all: a long red thread of wool, wound into a ball.

"CHOO CHOO! CHOO CHOO!" and Toby brought them back to the Sparkle-Ice Cave.

But right at the entrance of the cave there was a very narrow passage, between two walls of ice. And through that passage blew the wind: a mischievous wind, cold and strong.

The children moved forward in a line, holding the basket tight. But just as they reached the narrowest spot... ROOOF! A gust of wind hit the basket and blew half of the things away! Pot holders, dish towels, and corks rolled everywhere, scattered across the slippery ice.

"Oh no!" cried Dash. "Everything flew away!"

"We'll never make it," said Ziggy, with a sad voice. "It's too hard."

Skye looked at the pieces scattered here and there, and her eyes filled with tears. For a moment it really seemed like there was nothing left to do.

But not Lily. Lily clenched her fists and her blue eyes shone with courage. "Let's not give up!" she said loudly. "One piece each, we'll pick them all up. Together we can do it!"

She got down on her hands and knees and began to gather them. "Ziggy, you grab the pot holders over there! Dash, you're the fast one, catch the corks before they slide away! Skye, hold the dish towels tight!"

And so they did. Ziggy jumped and grabbed the pot holders. Dash darted like lightning and scooped up every cork. Skye hugged the dish towels against her chest, so the wind couldn't carry them off. One by one, they put everything back in the basket.

"But the wind will make them fly away again," said Ziggy, worried.

Then Lily pulled out the ball of red thread and smiled. "Look! Let's tie everything together with this thread. If every piece is joined to the others, the wind won't be able to pull them apart!"

And so, with the red thread, they tied the pot holders to the corks, the corks to the dish towels, the dish towels to the sock-warmer. All the pieces from everyone, joined into one big red ribbon. The wind blew again, ROOOF, but this time nothing flew away. The thread held everything tight.

They crossed the passage without losing anything else, and stepped into the sparkling cave.

Then they all set to work together. With the pieces tied by the red thread, they built soft little cloaks: a pot holder here, a dish towel there, the warm flour sock on the back, a cork stopper for a button. They made one for each hedgehog.

Gently, Skye wrapped the smallest hedgehog in its little cloak. Lily covered the mommy hedgehog. Ziggy and Dash tucked in the other two babies.

Little by little, the hedgehogs stopped shivering. The brrr brrr of their tiny teeth stopped. Their little noses turned warm and rosy.

"How wonderful," sighed the mommy hedgehog. "We're not shivering anymore. Thank you, little friends."

The three hedgehogs curled up close to one another, wrapped in their red cloaks, and closed their happy little eyes. In the cave of ice, now, there was a warm little corner that felt like home.

Skye wiped away a tear, but it was a happy tear. Lily smiled, tired and content.

"Did you see?" she said. "On our own we didn't have enough to warm them all. Skye's pot holders, on their own, were not enough. Dash's corks, on their own, were not enough. Ziggy's idea, on its own, was not enough. But all our pieces, tied together by the red thread, became warmth for everyone."

The red balloon swayed happily and whispered, for the very last time: "That was the secret. The warmth was not in any single thing... it was in all of you, together."

Then, softly, it flew away out of the sparkling cave, up toward the blue sky, to look for other kind-hearted children.

Outside, Toby was waiting for them, with his happy whistle. "CHOO CHOO! CHOO CHOO!" The children climbed aboard, their cheeks red from the cold but their hearts all warm. And Toby, before taking them home, said his rhyme:

"CHOO CHOO, what a team, oh what a fine day,
a small thread of wool chased the cold wind away!
Alone just a scrap, but together a treasure,
you warmed the cold hedgehogs, oh what a pleasure!"

And as the little train raced over the dewy hills that sparkled like diamonds, the four friends held hands, happy. They had learned something true: no one, on their own, had enough. But by putting together the pieces of each one, tied tight as if by a red thread, they had done something great.

Because together we are stronger. And many little ones, all together, can warm the whole world.