At the end of World War II, thousands of former Soviet POWs, repatriated from Germany, were sent to Siberia by Stalin, to be ‘re-educated.’ The Edge is set in one such labour camp, on the edge of a dense forest. Despite being a war hero, Ignat, a disgraced Red Armytrain engineer, is sent to the camp as punishment for destroying the fastest train in the Soviet Union during a reckless race. Upon arrival at the camp, Ignat quickly establishes a reputation for devotion to the labor camp's one railway engine. The railway line goes no further west than the camp because a bridge was washed out just before the start of the war. On a hunch, Ignat follows the line west, swims the river at the washed out bridge, and continues down the railway line. He soon discovers an abandoned railway steam engine trapped on the wrong side when the bridge washed out. Living inside the cab is a young German woman, Elsa, surviving by hunting and gathering. Ignat and the woman start out fighting each other and are unable to communicate due to the language barrier. Eventually they start to work together, both in repairing the steam engine to run, and effecting makeshift repairs to the washed out bridge. They arrive back in camp with the awful looking steam engine and continue to work together on repairs. Elsa and Ignat become isolated from camp people. Ignat for his devotion to his newly found railway engine, and the German woman simply by hatred for Germans from the war. Camp members summon the distant political commissar, who arrives by special train. The commissar is brutal, shooting and killing a Russian woman accused wrongfully of sleeping with the Germans. He locks up Elsa in a boxcar attached to his train and departs the camp. When Ignat learns Elsa has been taken away, he chases down the commissar on the train engine found in the woods, running on parallel tracks. Further back, the camp's main train engine, carrying many of the camp members, is also chasing down the commissar's train, angry over the brutality they witnessed. Ignat's train is faster, he manages to get ahead of the commissar's train in a winter race through the woods. He stops the Commissar by cutting him off at a rail junction, and knocks him out. Later the arriving train with much of the camp personnel find the commissar and send him packing down the rail line on a bicycle. The final scene shows Ignat and Elsa making their escape on a pump type railway hand car, to start a new life elsewhere in the Soviet Union.
