As the Crimean War rages, British Capt. Eric Evoir (Jean-Pierre Aumont) and Maj. Bruce Lindsey (Richard Stapley) are sent to the Crimea to protect a top-secret cannon capable of blasting through the walls of a nearby Russian fort. Lindsey, unfortunately, is captured by the Russians, who subject him to brutal interrogations. It's up to Evoir to save him. Along the way, Evoir meets a beautiful gypsy girl (Paulette Goddard) and begins an affair as intense as the war itself.