Three teenagers break into an old dentist’s office and find an underground city hidden below it. Strange clues, a glowing machine, and Olek’s sudden disappearance turn the search into something far stranger than a dare.
The old dental surgery on Florianska Street had been the subject of rumours for years. People passed it with a glance and a shiver, as if the building itself might remember every tooth it had ever touched. For Julia, Olek and Iga, that made it irresistible. By the time the June sky had gone dark, they had already decided they were going in.
They slipped through a window that had been left slightly open in the waiting room. The air inside was stale and sharp, carrying the faint chemical bite of disinfectant and dust. Their footsteps sounded far too loud in the empty corridors. Old lamps hung crookedly from the ceiling, swaying a little in the stillness. X-ray films lined the walls in wavering rows, each one showing the shadow of a stranger’s mouth. Under some of them, someone had written notes in a hard, cramped hand. The same words appeared again and again: decay. fracture. mystery.
Olek was the first to notice that one of the office floors did not sit quite right. The tiles near the desk were too neat, too smooth, as if they had been laid over something meant to stay hidden. He knelt, ran his fingers along the edge, and found a shallow indentation no wider than a coin. When he pressed it, there was a low click.
The slab shifted.
At first it moved only a fraction of an inch. Then, with a quiet scrape of stone against stone, it slid aside and exposed a narrow stairway dropping into darkness. Cold air rose from below. Not basement air. Something cleaner. Stranger. Julia exchanged a glance with Iga, and without a word the three of them began to descend.
The space beneath the surgery was impossible.
It opened into a vast underground chamber that looked less like a room than a city built from light. Walls of pale crystal rose in broken towers, their surfaces gleaming like polished enamel. Walkways crossed over channels of glassy stone. Thin strips of light pulsed along the floor, as if the whole place were still awake. In the centre stood a machine no one could make sense of at first glance: enormous, gleaming, and shaped like a toothbrush from a nightmare, its metal bristles ticking softly against an invisible surface.
Julia stepped closer. A brass plate fixed to the machine carried a single line of text: Cleanliness is the key.
Iga stared at the floor around it. Scattered across the tiles were small coloured spheres, smooth and bright, like sweets left behind in haste. One of them rolled when she touched it, revealing a symbol etched into the crystal beneath. Before she could bend lower, Olek made a strangled sound.
He clutched his jaw. His face had gone white.
“It hurts,” he whispered, but the word barely left his mouth.
Then he was gone.
No shout. No fall. Just one blink, one flash of metallic laughter echoing through the chamber, and the empty space where he had been a second before.
The lights overhead flared violently. Somewhere in the dark beyond the crystal walls, a door began to move.