Geheimcode B/13 (1967)

Colonel Maratka and Major Kalasz, employees of the Czechoslovakian defense forces, are facing a difficult task. They must complete a mission that is important for the security of their country. The Prague headquarters of the state security service had previously received information from the GDR that West German military intelligence had apparently succeeded in deciphering the secret code B/13 used in the field of missile armament.