Episode 6 - S1.E6

River transports on the Volga are attacked by new magnetic-acoustic mines. The defense of Stalingrad is threatened. To help our engineers deal with the new enemy mines, Kuznetsov and Beria combine their intelligence. They have the difficult task of transferring a Soviet spy from Germany - engineer Zinaida Stern, who will be engaged in the development of new anti-mine minesweepers.