It was a warm summer night when three dental students - Ania, Olek and Bartek - decided to venture into the abandoned underground under the old university department. There was talk that something unusual was hiding in the winding corridors stretching underneath the city, and recently samples of carious bacteria had started to disappear from the laboratory for unknown reasons. Anna, the most sceptical of the group, didn't believe any of the legends, but Bartek insisted that the strange noises and lights seen at night beneath the department were related to these mysterious disappearances. The lights of their torches were dancing across the old bricks when Olek accidentally pressed a hidden panel in the floor. With a hiss, the entrance to the unknown tunnel opened. The group was swept away by a wave of adrenaline rush. Inside, there was a peculiar, sour smell that reminded Olek of the scent of laboratories after bacterial cultures. The deeper they went, the more traces they encountered - plaque-like deposits, bizarre formations on the walls that looked as if someone had painted them with a toothbrush. Eventually they reached a huge chamber. In its centre rose a structure resembling a giant tooth, around which hundreds of miniature figures clambered. Each was shaped like bacteria - clearly visible feelers, slimy bodies and some even had toothbrushes in their microscopic hands. Then they heard a loud whisper: - People ... people have come! A being, a little larger than the others, slid out of the shadows - it was wearing a coat of dental floss and a crown of enamel fragments. She held out something that looked like a syringe of toothpaste towards them. - 'You have a choice, newcomers,' she said in a menacing, bubbling voice. - Either you help us gain access to the surface, or your jaws will become our new home! The students looked at each other. They carried neither toothbrushes nor toothpaste - only knowledge and imagination. Would they dare to take on the bacterial challenge? What will they answer in this bizarre situation?....