Ada and Max find a hidden tunnel beneath their school, where mint-scented walls, living gel creatures, and a threat from Prince Prodigy turn an ordinary bathroom into something far stranger.
Ada had always been the sort of girl who noticed what other people missed. So when she spotted a thin crack in the bathroom tiles beneath the old school on Cherry Street, she stopped dead and stared at it as if it might blink first.
The crack had been there for days. But now the bathroom smelled faintly of mint, a sharp, clean scent that didn’t belong in a place that usually smelled of soap, damp socks, and too many children. Since the new caretaker, Janek, had started mopping the floors, the smell had grown stronger, as if someone had tipped an entire tube of toothpaste into the air vents.
After lessons, Ada came back with Max, her best friend from class. Max came reluctantly, with the expression of someone who expected to be told off at any moment, but curiosity tugged at him harder than caution.
"There’s something under here," Ada whispered, crouching by the wall. She pressed her ear to the cold tile. "Listen."
Max knelt beside her.
At first, there was only silence. Then came a faint rustling sound, soft and busy, like a hundred tiny brushes sweeping in time.
Max swallowed. "That is not normal."
Before Ada could answer, the crack jerked wider. One tile slid sideways with a dry scrape, revealing a narrow opening below. Cold, mint-scented air breathed out of it.
Ada reached in and touched something soft and slick, like gel. Then she looked at Max, grinned, and dropped to her knees.
The tunnel beneath the floor glowed a strange, bright green. The walls shimmered as though they had been polished with fresh toothpaste. Ada crawled in first, Max right behind her, and the passage curved downward into a cave that looked carved from white foam and light.
Tiny figures hurried across the floor, their bodies made of shimmering gel droplets. Each one had a tuft of bristling, toothbrush-like hair and bright green eyes that flashed when they turned toward the newcomers.
One of them stepped forward, trembling but determined.
"You came," it said. "Good. The grotto is in danger. Only you can stop Prince Prodigy."
Max stared at Ada, half thrilled and half terrified.
Then the wall behind the little creature shuddered.
A deep laugh rolled through the tunnel from somewhere far below, low and harsh and unmistakably pleased with itself.