It was Halloween, and the riverside town smelled of smoke and pumpkins. Lena, aged fourteen, put on a fox mask and a torch on her wrist. Next to her walked Marcel with a sports camera, watching over the frames like a director. This year they didn't want candy, just answers and strong stories. They planned to check out the legend of the Tenement under the Bat, closed for years. The former lighthouse keeper was said to have disappeared there after the thirteenth ringing of the bell. Since then, the bell itself has been ringing on Halloween, at the same time. The librarian lent them a map from a forgotten book, covered with wax stains. In the margin someone had annotated: "Open the thirteenth staircase when the clock shows 21:13." Lanterns blazed in the gate of the tenement, and smoke moved like a cat. The stairs creaked under their trainers as they counted out loud the next steps. The thirteenth turned out to be hollow inside; the plank had given in with a nail. Inside lay a brass key on a black string and a note. "Don't look"-read Lena, smelling smoke mixed with roses. Marcel's phone vibrated; a map appeared with a point 'almost here'. A notification from Unknown flashed above the point: the location from the loft had been accessed. They stopped in front of a door with a bat, on which someone had scratched out the time. The key fitted perfectly, though it was as cold as the ice from under the bridge. From inside came a slow violin theme, reminiscent of their school's anthem. "Is this a joke?"- whispered Marcel, picking up the camera he had set to night mode. The phone showed "0 m from target", and the bell downstairs struck thirteen times. When the door handle vibrated on its own, Lena clenched her teeth and asked: "Who's there?" She was answered by the quiet, familiar, "You're already late, Lena"-just from behind the door. Marcel tapped the screen; a frame of their backs appeared on the preview. There was no one in the corridor, yet a shadow stood between them. "Is that a filter?"- Lena asked, though she could feel the mask warming her cheeks strangely. The notification flashed again: 'Don't look', this time sent from Lena's number. The violins sped up, as if counting their pulse; the lantern hissed and went out. The door vibrated a second time, and somewhere above it the old dusty air collapsed. A paper bat fell from an alcove, whirling until it stuck to the handle. Someone on the other side moved the chain, and the key in the lock turned by itself.