Chief accountant Porfiry Petrovich, who had a good time at the jubilee of his colleague, cashier Ivan Vodnev, climbs into the hut of the regulator and violates traffic on one of the streets of Leningrad. However, the guard Vasili Shaneshkin mistakenly delivers to the police station a non-escaped offender, but quite a decent cashier. To all other things, Vodnev, offended by the police, turns out to be the father of the bride of Shanishkin's Katya. Vasily admits his guilt, but, not daring to explain himself, leaves an angry Ivan Zakharovich with bad thoughts about the Soviet militia. Fortunately, the young sergeant will soon have the opportunity to prove to others the responsibility and integrity of the militia.