It is winter of 1941 in the besieged city of Leningrad. Soviet Counterintelligence learns that the Germans are preparing to sabotage the "Road of Life", the only way food and other goods are delivered to the city. Most likely, the saboteur is one of the drivers working on the frozen Lake Ladoga. The captain of the NKVD, Sergienko, must find and stop the enemy before its too late.
