Autumn 1941. Miraculously escaping from the Kiev boiler, investigators from the military prosecutor's office Rokotov, Mirsky and Elagina arrive in Kharkov, where evacuation is already in full swing. They have in their hands important information about the activities of the German espionage organization. New circumstances force them to linger in Kharkov. Indeed, together with the enterprises being evacuated, under the guise of refugees, further groups of German saboteurs are moving further east, whose purpose is sabotage and sabotage at military factories. Trying to open the channels for transporting scouts to the Soviet rear, Rokotov and Elagina find out that the organization operating in Kharkov is directly related to the Kiev group that they discovered a few hours before the city was surrendered. And the curator of both of these groups occupies a high post in the Main Military Prosecutor's Office.

A former policeman Pozhivaev once notices a leaflet on a post - "A dog has disappeared ...". After a couple of meters, he stumbles upon another ad - about finding a dog. It turns out that it was about the same dog. Pozhivaev decides to help deliver the dog to the owner, who turns out to be his neighbor... So the hero comes up with the idea to create a Service for the search and rescue of pets. It includes a self-taught mechanic Vitya Burkin, an avid computer scientist Garik and Mikhalych, a young authority on the bird market...