In the Undercity dormitory, life went on at its own pace - fast, loud and a bit frantic. The corridor smelled of pizza, coffee and a suspicious hint of something like football socks, and the fridge at the end of the kitchen was the heroine of numerous stories (most of which ended in an upset stomach or at least social failure). It was late on a Saturday when Adam, a perpetual biotechnology student, found a note in his yoghurt. Attached with a paperclip, with the letters punched out of newspaper: "RESPECT YOUR YOGHURT, SUPERMAN!". Adam looked at it in disbelief, as he didn't remember signing up to any yoghurt cult. He decided to start investigating. Kuba, the master of eating other people's sausages, and Dominika, the instant coffee with chilli specialist, immediately joined in. The three of them sat down at the kitchen table, covered with a tablecloth bearing the school's logo, planning extensive operational activities. Of course, all to the accompaniment of crisps, energy drinks and YouTube playing tomato soup songs sung by cats in the background. - 'It must be someone from our floor,' said Dominika, glancing around the closed doors to the rooms. - 'Or is the fridge living a life of its own? At that moment the kitchen door opened with a bang and Patrick walked in, famous for being able to tell jokes so dry that the lettuce in the fridge withered even on a Monday. He sat down and whispered conspiratorially: - 'Yesterday my Pepsi was signed "STRONGLY NOT TOUCH". And today it's gone. They all looked at each other meaningfully. The fridge suddenly made a sound like the swish of a kettle, and then something... knocked from inside. Adam clamped his hands on a paperclip from a note, Dominica straightened her coffee spoon and Cuba... gently moved behind a large packet of crisps. The air thickened with tension and paprika spice. Was someone in the fridge, or was it Dominica's next coffee that added fuel to the fire? No one dared to come closer. The fridge door trembled a second time. Everyone held their breath. Patrick decided to make a joke, but....