In December of 1944, Lionel Evans, an internationally renowned American conductor, is on a USO tour with his 70-piece symphony orchestra in newly-liberated Belgium. While fleeing from a German counterattack, Evans and his orchestra members are captured by a Panzer division and taken to an old chateau in Luxembourg. Despite orders to execute every prisoner, General Schiller, an avid music lover, commands Evans to give a private concert for him. Evans refuses in order to barter for more time. The presence of two U. S. servicemen hiding among the orchestra members further endangers the group's safety. The two men try to escape during a rehearsal, and one is shot down and the other killed by a land mine. Evans finally consents to give Schiller his concert if he will release Annabelle Rice, the wife of first violinist Victor and Evans' former mistress, who has futilely attempted to bargain for the players' lives. As the performance nears its end, Schiller leaves and gives his aide, Colonel Arndt, permission to kill the musicians. Armed partisans attack the remaining Germans, however, and help most of the orchestra members to escape. Although Evans is left to face Arndt, his life is spared when Schiller returns and shoots Arndt.