In the autumn of 1864, remnants of the Confederate States of America 5th Georgia Cavalry are prisoners of war in the Union (American Civil War) prison camp at Rock Island, Illinois. Sick and dying in deplorable conditions, they find a chance for survival when Union Captain Mark Bradford (Cornel Wilde) offers them release from "this stinking pesthole" like Bradford to fight Indians. Although promised that they will not be compelled to fight against their own, many of the Georgians resist the offer. Putting the decision to a vote, the issue is deadlocked when the last soldier dies before he can choose. Compassion for his men, and Bradford's sincerity, compels their reluctant commander, Col. Clay Tucker (Joseph Cotten) to break the tie by agreeing to the conditions offered.