The sports career of the talented young athlete Dima Reutov was under threat. The doping test conducted after the competition gave a positive result. Dima came to the police for help. Artyom came up with a plan to find out who decided to settle accounts with Dima…
 

A colonel from the anti-drug department addresses the operatives: their trained spaniels cannot detect the shipments of banned substances that regularly arrive in Moscow from Dushanbe. The informant calls the flight of the plane every time, a team of specialists and dog handlers leave, but there is no result… This time Mukhtar goes to the airport and barks at a passenger with a cat cage. Everyone thinks that the dog just reacted to the cat. But in vain…