While fighting in the Korean War, a Marine lieutenant is killed, leaving Sgt. Eddie Towler (Sidney Poitier) in charge. However, since Towler is black, he faces resistance from some of the men, most notably Pvt. Bracken (Paul Richards), a racist soldier from the South who doesn't hide his prejudice, and Sgt. Kincaid (Alan Ladd), who actually has more experience in the field. As Towler struggles to maintain order within his platoon, the men must continue to battle the enemy.