Batty pushed the heavy brass handle with both wings. The tiny door creaked open, spilling warm, golden light into the dark cave tunnel. It smelled wonderfully strange—like peppermint tea and dusty old paper.

Inside was a cozy room carved from earth, filled floor-to-ceiling with piles of odd treasures. There were mountains of single colorful socks, towers of tennis balls, and a hill made entirely of shiny house keys. Batty’s jaw dropped in amazement.

Suddenly, a pile of argyle socks wiggled, and a small mole wearing thick glasses and a miner's helmet popped out. "We are closed!" the mole grumbled, squinting at Batty. "The Department of Lost Human Things opens at dawn."

Batty adjusted his goggles politely. "I am not a customer, sir. I am Batty the Explorer, and I am slightly lost." The mole, whose name was Mortimer, softened his expression. "Ah, a flyer. You lot are terrible with tunnels," he chuckled.

Mortimer decided to show Batty his favorite artifact. He held up a bright pink plastic frisbee. "This is a giant's dinner plate," Mortimer explained seriously. Batty nodded in awe, tapping it with his claw. "Fascinating science," Batty agreed.

To get Batty home, Mortimer pointed to a large, smooth pipe labeled 'The Express Chute.' "It leads to the surface, but it is a bit fast," the mole warned. Batty saluted bravely. "Speed is my middle name!" he lied.

Whoosh! Batty shot out of the pipe and landed with a soft *plop* right into his home tree, wearing a stray sock on his head like a hat. Professor Hoot looked down from his branch. "I see you found a souvenir," the owl hooted softly.