Subscribing invisible. Tamnikov A.

1942. The design bureau of the Gorky aircraft plant is developing the latest Soviet fighter. Suddenly, the NKVD bodies are becoming known about the leak of secret information on this project. To identify the spy network, Major Maxim Shelestov is sent to Gorky. To calculate the "mole", Shelestov comes up with a tricky operation. He himself arrives at the plant as an engineer, and his comrades are being introduced into the local environment under the guise of... seasonal criminals...