In 1892, Caucasian settlers Wesley Quaid and his family are attacked by a Comanche war party who proceed to kill and scalp him and shoot his three children, while his wife Rosalee manages to escape, hiding in a thicket.
In Fort Berringer, New Mexico, Captain Joseph Blocker rounds up an escaping Apache family and brings them back to the fort. He is then called to the office of Colonel Abraham Biggs, who informs him of his final orders before retirement, direct from the President: escort dying Cheyenne war chief Yellow Hawk, along with his family, back to their tribal lands in Montana. Under threat of a court-martial if he refused to follow the orders, he reluctantly accepts, despite his history with the chief, who was responsible for the death of several of his friends and comrades. Blocker chooses the detail that will accompany him: his trusty old friend Sergeant Thomas Metz; long-time aide Corporal Woodson; and promising newcomer Lieutenant Kidder, fresh from West Point. Biggs also assigns to the detail a young French-speaking recruit, Private DeJardin.
They begin their journey, but diverge from their path to investigate the charred Quaid house. Inside they find the emotionally scarred Rosalee, who, though initially hostile towards the Cheyenne family because of the previous attack, agrees to sleep in their camp after some coaxing from Blocker. The next day, she’s convinced to bury her family and join Blocker’s detail until their next stop-over. They are soon ambushed by the Comanche party, resulting in DeJardin’s death and Woodson being seriously wounded. After this attack, Yellow Hawk convinces Blocker that it is in everyone’s best interest to unchain him and his family. The next day, the bodies of the surviving Comanche party, who had managed to flee during their previous encounter, are discovered dead. Blocker deduces that Yellow Hawk and his son, Black Hawk, killed them thanks to Metz allowing them to leave the camp during the night.