After hours in the chemistry lab, Alicja, Arek, and Zuza find a jar marked Dentis Lux among their toothpaste tests, and the room begins to behave as if it is hiding something.
Maria Skłodowska-Curie School in Zielona Dęba was the kind of place that usually ran on a strict, familiar rhythm: bells, homework, tests, corridors full of half-finished conversations. Alicja liked that about it. Nothing surprised her there. At least, nothing ever had.
Tonight, though, the chemistry lab felt different. The building had gone quiet hours ago, and only their desk lamp kept the room from sinking into darkness. Alicja, Arek, and Zuza were still there, working on a project about oral hygiene and comparing different toothpastes on the clean, polished teeth of a shark the biology teacher had brought in for the demonstration. The tray of samples, the smell of mint and disinfectant, the glassware lined up under the shelves - it all looked ordinary enough, until Alicja opened one of the old cupboards in search of a jaw model and found a small, dusty jar tucked behind a stack of cracked beakers.
The label was handwritten in neat, faded Latin: Dentis Lux.
She held it up. The lid was cold in her hand. When she twisted it open, a sharp mint scent escaped, so clean it almost stung. Inside was a pale granulated substance that caught the light like crushed crystal.
Arek leaned over her shoulder. “Secret ingredient?” he murmured, trying to sound amused, but his voice had gone thin.
Zuza pulled their textbook closer and squinted at the label. “Dentis Lux,” she read. “Tooth light. That’s not a normal lab label.”
Before Alicja could answer, the overhead lights flickered once, then again, as if something outside the room had brushed against the power. A faint sound drifted through the door - not footsteps, not quite, but a slow, dry crunching, as if someone were chewing on glass in the corridor.
Arek crossed to the window and looked out. The hallway beyond was empty, washed in the weak yellow glow from the exit sign. Then the room went still in a way that made Alicja’s skin tighten. The jar in her hand seemed suddenly heavier. The mint smell thickened, turning cool and metallic.
The lights died.
In the blackout, a pale glow bloomed from the table, faint at first, then stronger, lighting the shark teeth, the scattered notes, and the three of them staring at one another in silence. The jar of Dentis Lux was shining now - not reflecting the lamp, but glowing from within.
And from somewhere in the dark corner of the lab, something shifted and began to move toward them.