Deep beneath the creaky floorboards of Cooper’s bedroom, where the air smelled like old library books and warm cocoa, there lay a secret. A secret so big, so tickly with excitement, that it made the soles of Cooper’s feet itch every night. This was the Underground World of Lost Objects—a place where mismatched socks, forgotten hair clips, and one very grumpy rubber duck named Quackers all lived together in a jumble of glitter and giggles.

One evening, as Cooper wiggled his toes into his slippers (which felt like walking on clouds made of marshmallows), he heard it: a sound like a teakettle singing mixed with a bicycle bell. Ting-ting-psssssh! His ears perked up. The noise came from under his bed—no, deeper than that. From the floor. From the dirt. From the Underground World itself!

Cooper dropped to his knees, his pajamas scratching like a cat’s tongue against his skin. He pressed his ear to the floorboards. Chugga-chugga-chugga! The sound grew louder, rattling his teeth like popcorn kernels in a hot pan. Then—POP!—a trapdoor swung open right beneath his nose, and the smell of burnt toast and strawberry jam whooshed up. Down, down, down he tumbled, landing in a pile of something squishy and warm. Splortch! It was a mountain of lost mittens, all knitted together like a giant, lumpy blanket.

"Oof! Watch where you’re flopping, kiddo!" squeaked a voice. Cooper looked up to see Quackers the rubber duck, his yellow feathers ruffled like a dandelion in a storm. One of his eyes was missing, and the other blinked slowly, like a sleepy traffic light. "You’ve landed in the Underground World of Lost Objects, and let me tell you, we’ve got a problem."

Cooper’s heart did a little flip, like a pancake on a Sunday morning. "What kind of problem?" he asked, brushing a stray button off his sleeve. It smelled like peppermint and old birthday cards.

Quackers sighed, his beak drooping like a wilted flower. "The Dream Train. It’s broken. And if it doesn’t leave tonight, the children of the world won’t get their dreams. No flying on dragon-back. No ice cream that never melts. No pillow forts that reach the moon!" He kicked a loose shoelace, and it coiled around his foot like a sleepy snake. Zzzip!

Cooper’s stomach twisted. He imagined his little sister, Lily, waiting for a dream about unicorns, her eyelids fluttering like butterfly wings. "We have to fix it!" he said, his voice bouncing off the walls of the underground tunnel. The tunnel was lined with lost things: keys that jingled like wind chimes, marbles that rolled like thunder, and a single sock that smelled like buttered popcorn and dog kisses.

Quackers led him through the winding paths, past a waterfall of lost coins (splash-splosh!) and a bridge made of bent paperclips (creak-squeak!). Finally, they reached the Dream Train. It was a magnificent thing, all shiny and silver, with a smokestack that puffed out clouds shaped like bunnies and stars. But the engine was silent. The wheels were stuck. And worst of all—the conductor, a tiny man with a hat as tall as a traffic cone, was sobbing into a handkerchief that smelled like lavender and bad decisions.

"Oh, woe is me!" the conductor wailed. "The Dream Train needs a spark to start, and I’ve lost mine! Without it, the train won’t go, and the dreams won’t flow!" He blew his nose with a sound like a goose honking. HONK!

Cooper scratched his head. A spark? What kind of spark? Then he remembered—his favorite toy car, the one he’d lost last summer. It had a little engine that vroomed when you pulled it back. Maybe... just maybe...

"Quackers," he said, his voice wobbling like jelly. "I think I know where to find a spark." He closed his eyes and concentrated. Vroom-vroom! The sound echoed in his mind, and suddenly, he felt it—the tug of the Underground World pulling him toward his lost toy. His hands tingled like they’d been dipped in fizzy soda.

With a deep breath, Cooper reached into the air and—PLUCK!—he pulled out his toy car. It was covered in dust and smelled like summer rain and grass clippings. He wound it up, his fingers slipping on the tiny key. Click-click-click! The car’s engine whirred to life, and a tiny spark shot out, bright as a firefly.

"Here!" Cooper said, holding the spark out to the conductor. "Will this work?"

The conductor’s eyes widened like saucers. He snatched the spark and popped it into the train’s engine. FIZZ! POP! BANG! The train shuddered, then roared to life, its wheels spinning like a hamster on a wheel. Chugga-chugga-CHOO-CHOO! The smokestack puffed out a cloud shaped like a high-five, and the whole train glowed like a nightlight.

Quackers clapped his wings (or at least, he tried to—one wing was still missing). "You did it, Cooper! The Dream Train is saved!"

The conductor tipped his tall hat. "All aboard! Next stop: Dreamland!" The doors of the train slid open with a whoosh, and out poured the sweetest smell—like cotton candy and fresh-baked cookies. Cooper’s sister, Lily, would get her unicorn dream after all.

As the train chugged away, Cooper felt a tap on his shoulder. It was Quackers, holding out a single, shiny button. "For bravery," he said. "And for not crying when you landed in the mitten mountain."

Cooper grinned and pinned the button to his pajama top. It felt cool and smooth, like a pebble from a stream. Then, with a final wave, he climbed back up the trapdoor, the Underground World humming softly beneath him. As he snuggled into bed, the sound of the Dream Train echoed in his ears—chugga-chugga, chugga-chugga—and he drifted off to sleep, dreaming of sparks, mittens, and the bravest little boy in the world.