Omnibus film featuring early works by Chekhov

In the third movie colonel Zorin is investigating two murders.

On the way for fishing Leonid Karetnikov finds the body of a man on the roadside and admit a car driving out of there. While Karetnikov called the police, the body was gone. Also disappeared the bag with tools to crack safes, lying next to body. Pursuing the investigation of the case, Colonel Kornilov states that the victim is probably Lev Kotlukov - known "safecracker" nicknamed Leo the Boar. Also, it looks like he got hit by a car belongs to citizen - professor of the Institute, which has no relation to criminal organizations. To reveal the intentions of criminals, Kornilov decided to send his man Major Bugaev undercover to the gang.