That morning Lily, Ziggy, Skye, and Dash had built a castle of cushions in the living room. There were towers of pillows, bridges of blankets, and a door made from the back of the couch.

"I'll be the guard!" said Lily, climbing to the top of the tallest pile. Her blue eyes sparkled, the way they always did when it was time to be brave.

"And I'll race around the castle!" shouted Ziggy, who could never sit still.

Dash slid across the floor like a lightning bolt and tumbled feet-up into the cushions. "Surprise attack!" he giggled. Skye, calm as ever, carefully fixed each cushion that fell, because she liked everything to be in its right place.

Outside, the sky was gray and lazy. It wasn't raining, but it seemed like the world was still asleep. Then, all of a sudden, a light breeze slipped through the window curtains. A gentle wind that seemed to whisper, like when someone tells you a secret close to your ear.

And with that wind came a sound the children knew very well.

"CHOO CHOO!"

In the garden, popping up out of nowhere, was Toby the Magic Train, with shiny wheels and smoke that did somersaults in the air.

"CHOO CHOO! Climb aboard, dear friends, don't wait around,
a castle sits up high where laughter can be found!
Round and round a stair, past a wall that lost its way:
only the heart remembers what was lost one day."

The four children looked at each other with wide-open eyes. A castle? A forgetful wall? They didn't need to be told twice and jumped aboard.

The little train raced among the clouds and then stopped in front of a very tall castle. In the middle rose a narrow, narrow tower that went up, up, up until it poked through the clouds.

"This is Cimalta Castle," whispered the wind among the leaves.

But the castle was sad. Its windows were dark, and not a single laugh could be heard.

Ziggy picked up some colorful little papers that were fluttering here and there. "Look, there are drawings! They look like memories."

"They're the castle's memories," said Skye gently. "But they've all gotten mixed up."

Just then, the whispering wind blew harder and snatched the papers from Ziggy's hands, carrying them up, into the tower.

"Hey! Come back here!" shouted Dash, trying to catch them with a silly jump. But the papers had already escaped up the stairs.

Lily clenched her fists. "If the memories are up there, then up there we go. Come on!"

The tower door was open. Inside was a staircase that turned and turned, like a giant stone snail. You couldn't see the end.

Ziggy dashed off running, but after a few turns he stopped, out of breath. "Ugh, it always looks the same! It never ends!"

"My legs are going all wobbly-wobble," said Dash, sitting down on a step.

Skye looked up and sighed. "It's so tall..."

But not Lily. Lily took Skye's hand and said: "One step at a time. I'll go first, and you come behind me." And she started climbing again, as tenacious as ever.

Halfway up the tower, in a dark corner full of old trunks, they saw a little light floating in the air. It was a pencil. But not just any pencil: it floated all by itself, leaving a glowing trail behind it, and it smelled of wood and graphite.

"A flying pencil!" whispered Ziggy.

The pencil came closer and spoke with a tiny voice, a whisper barely, barely heard, in tune with the wind. "I draw what is true. I am the keeper of this dwelling."

The children looked at each other, confused. "Dwelling? What does dwelling mean?" asked Dash, scratching his head.

The pencil drew a little glowing house in the air. "Dwelling means home. The place where you live, where you come back in the evening," it whispered.

"Ah, a home!" said Ziggy. "What a nice new word: dwelling!"

"Will you help us put the memories back in place?" asked Lily.

"I only give half-clues," whispered the pencil, and as it said this, a little drawing slipped out: three sparkling little stars. It got emotional, and when it got emotional it drew stars without meaning to. "The answer you must find with your heart. Climb up. At the top is the wall that forgot."

So they climbed some more, with the pencil lighting the way. The wind whispered through the little windows, sometimes sweet, sometimes mischievous, and at every turn it seemed to say mysterious words.

All at once a step creaked under Dash's foot and dropped down suddenly. "Aaah!" Dash wobbled backward.

Lily grabbed him by the shirt with both hands. "I've got you! Watch where you put your feet."

Everyone's heart was pounding. But Lily didn't let go until Dash was safe again.

"Thank you, Lily," panted Dash. "That was close!"

"Together we don't fall," she said. And they started climbing again.

Finally, after the last turn, they reached the top. There was the attic: a round room full of little papers fluttering everywhere, like crazy butterflies. They were the memories, all mixed up. And on one wall, among the dust, was a great stone wall with ancient writing that glowed ever so faintly.

"This is the enigma," whispered the pencil. "An enigma is a riddle that is very old and very hard. If you solve it, everything will go back to its place."

On the wall, in glowing letters, a question was written:

"What is the most beautiful place in the world?"

The children thought about it.

"Easy!" said Ziggy. "The most beautiful place is where there's a treasure full of gold!"

Ziggy stepped up and said out loud: "A treasure of gold!" But the wall stayed dark and cold. Wrong.

"Wait, let me try," said Dash. "The most beautiful place is a great big castle, all for us!" But the wall didn't light up, not even a little.

Skye stepped forward shyly. "Maybe... a mountain of sweets? Of candies and cookies?" But nothing. The wall stayed dark, and the papers kept fluttering sadly.

The children began to lose heart.

"We'll never do it," said Dash, in a tiny little voice.

"It's too hard," sighed Skye.

But Lily didn't give up. She never gave up. She sat down in the middle of the room and began to look at the fluttering papers, one by one, carefully. And the more she looked, the more she noticed something strange.

"Friends... come and see," she said. "Look closely at the memories."

They all came closer. On one paper there was a mommy holding a baby in her arms. On another, a daddy cuddling a sleeping little girl. On yet another, grandparents hugging their grandchildren. In all of them, every single one, there were people hugging each other.

"It's always the same thing," said Lily, and her blue eyes lit up. "The most beautiful place isn't gold, it isn't a castle, it isn't sweets... It's where there's someone who loves you!"

The pencil drew a shower of little stars: it had gotten so, so emotional.

Lily stood up, went closer to the wall, and whispered, gentle as the wind: "The most beautiful place in the world is home, where there's someone who loves you."

For a moment, nothing happened. Then the wall began to glow, softly, then more and more, with a warm, golden light. The ancient letters all lit up together.

And then the magic happened. The papers stopped fluttering wildly and, one by one, went to their right places on the walls, like little pictures in a home. The attic was no longer messy: it had become beautiful, warm, and cozy.

"We did it!" shouted Ziggy, jumping.

But the biggest surprise was still to come. Through the little tower windows came a light the children had never seen before. In the sky, where before there had been only gray clouds, ribbons of green and purple silk now danced: a colorful aurora that moved gently, like a hug made of light.

"How wonderful," whispered Skye, her eyes shining with joy.

"Now the castle remembers who it is," said the pencil, happy. "And you too will always remember which is the most beautiful place."

Together with the pencil, the children drew a little glowing frame around each memory they had found again. Every time they finished a frame, the drawing became real and glowed on the wall. The attic filled with light, with happy memories, and with laughter.

When they had finished, they heard a familiar sound rising up from the garden.

"CHOO CHOO!"

Toby the Magic Train was waiting for them. They went down the turning staircase, light and happy now, and climbed aboard. The pencil stayed at the tower door, waving with a trail of little stars.

As they headed back home, among the clouds lit by the aurora, Toby said:

"CHOO CHOO! Head for home with a smile so bright,
you woke the old wall and you filled it with light!
The nicest place isn't gold, and it isn't far away:
it's where someone waits for you and holds your hand each day."

That evening, when each one went back to their own mom and dad, the children ran to hug them tight. Because now they truly knew: you can visit the tallest towers, magic castles, and skies full of colors, but the most beautiful place in the world is always your home, where there's someone who loves you.

And Lily, before falling asleep in her mom's arms, smiled. Because that day, she hadn't given up. And she had reminded everyone of the most important thing.