Kudryavtsev gives his gun to Nikolai Zvonarev in a locker room for storage in the guise of a valuable gift. Zvonarev puts the pistol with his architectural project in his super reliable Japanese locks case and puts it in the locker. After the game, it turns out that the case was gone. After 6 hours, Zvonarev must hand over his project to architectural commission, and Kudryavtsev already has a second loss of weapons, which threatens with big trouble. Semyon has 360 minutes and a mate to find the criminal and the contents of the case.
—Andrey Da!