April 1941. According to intelligence received by the Chekists, a fascist sabotage group plans to blow up one of Moscow's defense plants. To find out the plans of saboteurs working under the auspices of the German embassy, the NKVD sends one of its best employees, Sergei Biryukov, to the plant. He finds contact with the fascist agent Keller and finds out that the explosion is scheduled for June 21...
Georgiy Yumatov
Dmitriy Masanov
Valentin Grachyov
Nikolay Grinko
Fyodor Nikitin
Igor Dmitriev
Arkadi Tolbuzin
Tamara Syomina
Irina Korotkova
Nikolay Grabbe
Ivan Ryzhov
Lyudmila Gurchenko
Tatyana Konyukhova
Lyudmila Shagalova
Irina Kolpakova
Valery Panov
Valentin Bryleev
Igor Bezyaev
Aleksandr Grechanyy
Ella Nekrasova
Aleksandr Smirnov
Emmanuil Geller