The Marie Skłodowska-Curie School looked quite ordinary - at least in the daytime. A white, five-storey building with a grey roof, rows of large windows and, in front of the entrance, a tall clock that chimed its metallic ding-dong every full hour. But Kinga was well aware that the place lived a different life after dusk. It was Friday, the last day of June. Lessons were over and most of the students had run out into the schoolyard, shouting for joy about the holidays. But not her and Michael. They both belonged to the school's film club - today they had the first 'Movie Night' in the school's history. The club consisted of just five people, but for various reasons only two of them stayed that night. - 'Oi, Kinga, are you seriously not afraid to sleep here alone? - Michael smiled half-heartedly as they stayed in an empty classroom on the third floor. - You've been here so many times after hours! - replied Kinga, feigning indifference, although she felt a gentle prick of anxiety. - Besides, there's still Mr Marek from security. He promised to look in every hour. The room was full of soft cushions, popcorn was already lying ready on the table and the projection screen reflected the warm light of the projector. As it grew dark outside and the wind rustled the tall poplar trees, Kinga felt herself gaining courage. She sat down in the front row and glanced at the clock outside the window from a casual angle. Its hands stood still at 23:07. - Look, the clock has stopped," she remarked. But Michael just shrugged his shoulders. They had just watched the third film when suddenly something crackled in the corridor. The light flickered, the image on the screen disappeared for a moment. They both looked at each other, but neither spoke a word. After a moment, they heard a creak - as if someone was slowly opening the door from the room opposite. - After all, Marek was supposed to be downstairs... - whispered Michael. Kinga picked herself up from the floor. She felt that something strange was happening in the school. Through the glass of the door she saw a faint flash of blue light in the corridor, which pierced the darkness for a moment. Michal was trembling with emotion, but he moved behind her. They looked out into the corridor. All the doors were closed except one, which swung open slightly. It was room 217 - an old history classroom that no one had entered for months because it needed renovating. A soft, dragging sound came from inside, reminiscent of the quiet beating of a clock. And then Kinga noticed that the watch on her wrist had also stopped exactly at 23:07. Michael pressed the door handle with a quick movement. When the door opened wide, they saw something inside that they had not expected at all....