Matthew yawned protractedly, stretching on the creaky bed in room number 311. He had the feeling that Mondays at boarding school always start with an earthquake and then the tension only increases. This time, however, it wasn't the maths assignment or even the upcoming English test that made him feel slightly anxious-just the fact that he couldn't find his second black sock again. And not for the first time this week. Cuba, his roommate, laughed as he watched Matthew frantically dig through his drawers. "You should make a map of sock disappearances, man. It already looks like some kind of curse on this room!" Together with Sandra and Vera, who lived one floor up, the boys decided to create a Disappearing Socks Squad. Each of them had their own theory: Matthew suspected the P.E. teacher, because since the new lockers in the gym had come in, the most socks had gone missing. Sandra placed the blame on the tutor's lazy cat, which roamed the corridors at night. Wera claimed it was the work of a secret society of sock collectors. The plan of action was simple: set up a night patrol and install traps with melted cheese (the only thing the cat would be tempted by) and a hidden camera made from Kuba's phone, which hasn't been used for anything else lately anyway since his internet went down. Night fell quickly, and with it came a deep silence throughout the boarding school, broken only by the quiet snoring of colleagues behind the wall and the occasional slam of doors opening in the corridor. Sandra, with torch in hand and green mask on her face, looked more like a ghost than a detective, and Matthew hoped that even if they didn't find the culprit, at least they wouldn't die of laughter watching the footage of the night's action. Just when everyone was almost asleep, a strange rustling sound came from the corridor, followed by a deafening clatter and... a quiet meow. The camera registered the silhouette of someone or something leaning out from behind the bathroom door. The four detectives looked at each other and, barely holding back a laugh at their own fear, moved into the darkness. The door swung slowly open behind the mysterious shadow....