1978. Major of the милиция (police) Alexander Merkulyev arrives in Sevastopol to visit a friend, expecting a quiet vacation. Instead of rest, the city awaits him—shaken by a series of brutal crimes. On the seashore, they find a mutilated body of a girl bearing signs of violence—and it is far from the first murder.
Alarm among the residents grows; rumors spread through the city about a mysterious criminal nicknamed “the Black Colonel.” Merkulyev joins the hunt for the killer. The investigation leads the operatives to Captain-Lieutenant Zvyagintsev—he is the one the victim was seen with shortly before her death. But soon it becomes clear that Zvyagintsev is nothing more than a womanizer and has nothing to do with the killings. And meanwhile, amid the “Black Colonel’s” crimes, yet another bloody episode suddenly appears…