The disappearance of a subway train with passengers, a series of paradoxical deaths of an unknown poison, the stealing of large sum of money at Sheremetyevo, a range of murders with "devil" inventiveness made to look like accidents - what unites these seemingly so different events? All of them refute the myth that there were no celebrated crimes in the Soviet Union. The investigation of all these complicated and dangerous cases is entrusted to the group of professional detectives - colonel Stary nicknamed as “Old Man”, and his trainees - Lieutenants Kotin and Sirota.