It was early morning, and the sun stretched slowly behind the hills. On the garden grass, tiny drops of dew had appeared, and they sparkled like little diamonds when the light touched them. Skye was kneeling on the lawn, her nose close to a blade of grass, watching one little drop that looked like a whole world inside a tiny pearl.

"Look!" she said softly. "Every drop has a little sun inside it."

Ziggy came hopping over like a spring, with his four cats trotting behind him. "I can see a rainbow in there!" he shouted, and he tried to blow on it to make it fly away.

Lily, with her bright blue and determined eyes, gathered the drops on the tip of her finger. "They're cold and light," she said. "I won't break them, see? You have to be gentle."

Dash, on the other hand, was running in zigzags on the wet grass, leaving slippery footprints. "I'm a dew skater!" he laughed, and he almost landed on his bottom.

That was when, from far away, a happy and familiar sound came along. "CHOO CHOO!" Out of the morning mist appeared Toby the Magic Train, with his shiny wheels and soft white smoke like cotton candy. He stopped beside the children and said, as always, in rhyme:

"Good morning, children! The dawn is bright,
climb aboard quickly, we're off in flight!
I'll take you far where the blue sea sighs,
where a little light in the darkness cries."

The children looked at each other with big eyes. A light that sighs in the dark? What did that mean? But with Toby you never knew where you were going, and that was the fun of it. They all climbed aboard, and Ziggy's cats curled up by the window. "CHOO CHOO!" and off they went, the little train rolling away lightly.

Toby ran through the fields, then through the sand dunes, until the air smelled of salt. But when they reached the seashore, the sun had already gone to sleep. It was evening, and a light fog was settling over the water, soft like a blanket. It made everything a little mysterious: the sea seemed to vanish inside a grey cloud.

"How strange," said Lily. "You can't see anything out there anymore."

Skye pointed with her finger. On top of a rock stood a lighthouse, tall and silent. But it was dark. Not one little light, not a single beam. Only darkness.

"The lighthouse isn't shining," whispered Skye. "And without its light, the fishermen's boats can't find their way home in the fog."

It was true. Far away you could hear the worried voices of the fishermen, rowing slowly without knowing which way to go. The children's hearts squeezed a little.

"We have to help them," said Skye. And the others nodded.

Toby whistled sweetly and opened his little doors right at the edge of the water. "CHOO!" And, as if by magic, the children found themselves sliding down, down, under the sea, without getting wet and breathing like little fish. They floated gently all the way down, where a beautiful place was waiting for them: the Whispering Coral Garden.

It was a place full of corals of every color, and tall seaweed that swayed like light curtains. The current made a sweet sound, like a whisper, that seemed to speak to those who listened with their hearts. But here too, just like up above, everything was in the dark.

"How sad," said Ziggy. "It looks like it's sleeping."

"Once upon a time," said a slow, warm voice, "this garden shone like a thousand lanterns."

The children turned around. From behind a coral came an old crab, with a slightly worn shell and two big claws that moved slowly. He walked sideways, the way crabs do, and looked at them with kind little eyes.

"Hello, my little ones," he said. "It's been so long since I've seen any children down here."

"Why is everything dark?" asked Lily.

Grandpa Crab sighed. "Because the light from the lighthouse up there used to reach all the way down here and make the corals shine. With these claws, I used to build little coral lights to brighten the seabed. But now the lighthouse is dark, and I... I've been left in the dark. And all alone."

He said a strange word. "I've become a hermit," he said.

Ziggy tilted his head. "A her... a what?"

Grandpa Crab smiled softly. "A hermit, my little one, is someone who lives all alone, far away from everyone else. Like me, down here, with no one to talk to."

Skye looked at him for a long time. While the others were thinking about the dark lighthouse, she was thinking about those words: all alone. She came close to the crab and gently touched one of his claws.

"Grandpa Crab," she said in her sweet little voice, "you didn't just lose the light. You lost someone to turn it on with."

The old crab stayed quiet. His little eyes grew a bit shiny. "It's been so long," he murmured, "since I forgot how nice it is to build something together with someone."

For a moment nobody spoke. Then Skye smiled, and in her smile was all the warmth in the world.

"Then let's build a new light together," she said. "One that brings the fishermen home."

Grandpa Crab straightened up on his little legs. "Of course! If we go back up to the beach, with what the sea washes ashore we can make a little boat. A boat that carries a flame, like a floating lighthouse."

The children clapped their hands. What a lovely idea!

They all went back up together to the beach, where the fog kept on dancing. They started searching in the sand. It was a little adventure: the night was dark, and it wasn't easy to find the right things.

Lily, as stubborn as ever, moved a heavy pile of seaweed and underneath found two sturdy sticks. "These won't snap," she said, pleased. "They'll be the hull."

Dash zoomed back and forth on the sand collecting seashells. "Look how many I've got!" he shouted, but he tripped over a little crab and rolled down a dune laughing, with the shells flying everywhere. "Oops! I've planted them all!" And everyone laughed, even Grandpa Crab.

Ziggy, meanwhile, had stopped to think. Then something sparked in his eyes. "Wait!" he said. "We need something to keep the flame lit even in the wind!" He ran toward the rocks, climbed up with his hands and feet to an old rusty lantern stuck between the stones. He jumped down with a big leap and showed it to everyone. "Here! Inside this, the flame won't blow out!"

Grandpa Crab nodded proudly. "Well done, my little one. The mind and the hands, together."

Calmly and patiently, the old crab joined the sticks with his skillful claws, tied them with the strongest seaweed, and set the shells all around so they would sparkle. On top he placed the lantern. The children helped him, one held, one pushed, one blew the sand away. And while they worked, the crab was no longer alone: he laughed, he told stories, he taught.

"Here's the secret, my little ones," he said at one point, looking at Skye. "The strongest light isn't the light of the lighthouse. It's the light of those who wait for you at home. That's why the little boats want to come back: not for the dock, but for those who hug them when they arrive."

Skye nodded, and felt her eyes grow a little shiny, but the good kind, the kind that comes when something is right.

At last the little boat was ready. They lit the tiny flame inside the lantern, and the shells began to shine like little stars on the water. Gently, they placed it in the sea. The lighthouse-boat floated softly, pushing its little light into the fog.

And then it happened. In the dark of the sea, one by one, the fishermen's boats saw that light. "Over there! There's a light!" they heard someone shout. And they began to row toward it, following it the way you follow a star. One after another, the boats found their way back to the harbor, and the fishermen came home, where their loved ones were waiting for them with lanterns lit and arms wide open.

Down in the Coral Garden, a wonderful thing happened: the light from the little boat reached all the way down to the bottom of the sea, and the corals, one by one, began to shine again. The garden glowed once more with a thousand colors, and the whispers of the current seemed almost to sing.

But the most beautiful thing wasn't the light. It was that Grandpa Crab, for the first time in such a long while, was not alone.

"We'll come back to visit you," Skye told him, hugging one of his claws. "We promise."

"We promise!" said Ziggy, Lily and Dash too.

The crab's little eyes shone brighter than the corals. "Then," he said, his voice trembling a little with happiness, "this is no longer an empty burrow. It's home. Because now I have friends who love me."

Toby's soft whistle rang out. "CHOO CHOO!" It was time to go back. The children waved goodbye to Grandpa Crab until the glowing garden disappeared behind them, and they climbed onto the magic train, tired and happy. As soon as they were seated, Toby said, as always, in rhyme:

"You've lit a light that is warm and bright,
not the lighthouse beam, but the heart's own light.
The finest home is not built of walls,
but of those who love you and hear your calls."

And as the little train carried them home, through the parting fog and the first stars, Skye looked out the window and smiled. She had understood something important: home is not a place made of walls. It's made of those who wait for you, those who hug you, those who light a little light for you.

And that night, falling asleep in the arms of her daddy Andrea, with mommy Elisa tucking her in, Skye felt that she, right there, was home.