American orchestra conductor Lionel Evans (Charlton Heston), during a show in recently liberated Belgium, is captured with his musicians when Nazi troops ambush them. Held captive and told they will be executed, the group gets a reprieve after one of the Nazi generals, Schiller (Maximilian Schell), a passionate fan of classical music, demands the group mount a concert for the Germans. Trying to bide their time before the show, Evans and the players focus on an escape plan.