An undercover policeman infiltrates a criminal gang. Film based on a real criminal case

Aleshin, a responsible Komsomol member, is sent by the district committee to work in the OBKhSS. However, the young man absolutely does not feel a calling to this business and submits a letter of resignation. The boss is ready to grant his request, but only after Alyoshin completes one very important task. The case is as follows: two criminals involved in currency fraud were found to have tickets for one session to the Udarnik cinema. It would seem nothing criminal, but these two used tickets are for the same place, but on different days. This seems strange to the operatives, and the authorities instruct Alyoshin to find out everything. The young man begins to unwind this business. The most ordinary ticket to a movie show suddenly turns out to be the password of criminals. Aleshin uses this information to infiltrate the gang.