Crossing the threshold of someone else's apartment, tenth-grader Sergei did not even think that he was crossing a dangerous line that would divide his life into “before” and “after.” All they wanted was to find out who had encroached on their quiet family life. But what he saw in the ill-fated house shocked the young man. Stacks of money, imported clothes, a supply of expensive alcohol - an honest person cannot afford this. And then everything happened in a fog... And now the entire city police were knocked off their feet, making plans to capture a dangerous criminal who had come from nowhere in a calm Siberian city...