In the 1860s, a prison wagon is transporting murderers Link Ferris and Tioga through Apache Indian territory to Fort Smith, Arkansas, where they will stand trial. Accompanying the wagon is Marshal Bill Haney, his assistant Tom and driver Jud. On an adjacent trail, Indian trader Jonah McAdam comes upon a small cavalry troop that has been slaughtered by the Apaches, led by Chief Yellow Claw. The only survivor of the attack is Capt. Matt Riordan, who orders McAdam to change his direction and take him to Fort Dragoon Wells. As they are about to load the dead soldiers in McAdam's wagon, the prison wagon approaches. Minutes later, a stagecoach carrying Ann Bradley, Matt's former sweetheart, her fiancé, Phillip Scott, and Mexican entertainer Mara Fay pulls up alongside them. Believing that Yellow Claw is about to join with Geronimo and attack them, Matt orders the marshal to free Link and Tioga from their manacles so that they can help in the group's defense. After burying the dead soldiers, the three wagons move on but suddenly come under attack by a small group of Apache. In the attack, one of the stagecoach's wheels is irreparably damaged, rendering it incapable of continuing. Determining that the prison wagon is too cumbersome to be of help, they add the wagon's horses to McAdam's team and head out. When they camp that night, Marshal Haney tells Ann that Link has killed eight men, the last a town marshal. The next morning, McAdam stabs and kills Jud, who is on sentry duty, then tries to escape in his wagon, but Link jumps on board before he can get away. As the two men struggle for control of the wagon, it overturns and crashes. Link overpowers McAdam and is about to shoot him when Matt stops him, warning Link that McAdam must stand trial for his crime. They then discover that McAdam's wagon has a false bottom in which they find rifles, ammunition and whiskey intended for the Apaches. After Yellow Claw attacks again and kills Tom, Matt drags McAdam toward Yellow Claw and threatens to kill the trader. With the elimination of their supplier of guns and whiskey at stake, the Indians withdraw. After the loss of McAdam's wagon, the group travels on foot, hoping to reach a relay station fifteen miles away, from which Matt can get word to his garrison to send help. During the journey, Ann explains to Matt that she is marrying Scott because he is rich and willing to offer her a degree of freedom. Ann also attracts the attention of Link and Tioga, a social outcast due to his ugly appearance, who tries to give her the present of a necklace, which she rejects. The Apache follow the group and begin to kill them, one by one. After burying Hopi Charlie, the stagecoach driver, they reach the relay station and find that the Apache have set it on fire. Mortally wounded in the attack, the station agent's wife expresses great concern for her daughter Susan. Tioga finds the little girl cowering in the station's cellar and befriends her. Later, as Susan and Ann sleep, an Apache creeps into the camp and takes the child, but Tioga rescues her at the cost of his own life. As he dies, the others realize Tioga's innate goodness and Ann accepts the necklace she had earlier rejected. Eventually, the group reaches the fort but it has already been attacked, the garrison massacred and the water salted. Matt then decides to seek help from Fort Bennington fifty miles away but, as they have only one good horse left, the men draw cards to determine who will go. That night, as Mara flirts with Matt and they kiss, Scott and Ann break up after he accuses her of being incapable of loving anyone but herself. Link rides out, but is brought back the next morning as a prisoner of Yellow Claw, who demands that Matt hand over McAdam in exchange for Link. As Ann tends Link's wounds, they grow closer. Matt and Link formulate another escape plan. Link sneaks up on the Indian encampment and sees McAdam inciting them to kill the remaining travelers. Link shoots and kills McAdam, then leads his pursuers into an ambush in which Matt and the others kill Yellow Claw and rout the remaining Indians. They then take the Indians' horses and head for Fort Bennington. Mara and Matt are now in love and just before the group enters the safety of the fort, Haney gives Link his freedom in gratitude for having saved them. After Link rides off, Ann decides to follow him.