Alexey Severtsev, who came to enroll at Leningrad University from Siberia, is cleverly deceived by experienced criminals. At the station, they manage to lure Severtsev into a deserted place, beat him and rob him. A young police sergeant Nikolai Zakharov is assigned to investigate this incident. Zakharov will show resourcefulness and courage, and, of course, will detain repeat offenders.