The Zacharys are a thriving and respected family on the Texas frontier. Father Will Zachary was killed by Kiowa Indians, leaving his oldest son Ben as the head of the family. Both Ben and his mother Mattilda are very protective of the Zacharys' adopted daughter, Rachel, who was adopted as an infant; her other brothers, Cash and Andy, treat her as they would any sister. The family is supported by their closest neighbor, Zeb Rawlins, the patriarch of a family whose shy son, Charlie, wants to marry Rachel. Ben is reluctant for this to occur; having long been aware that she is not actually his sister; he is in love with her. Ranchers from all around gather to prepare for a cattle drive to Wichita, Kansas. An old man thought to be crazy, Abe Kelsey, hides in the brush nearby after claiming that Rachel Zachary is an Indian. Believing this story to be a vengeful lie, Ben and Cash try to kill Kelsey; they manage to unhorse him but he soon steals a horse from their property. One night, a small group of Kiowa led by Lost Bird, appears and offers to trade horses to Ben in return for Rachel. Lost Bird claims that she is actually his sister, that an old white man told him this. Soon after, Charlie - to whom Ben has decided to give permission to court Rachel -- is killed by the Kiowa while returning home after visiting her. In her grief, Charlie's mother accuses Rachel of being a "dirty Injun". Ben leads the ranchers in tracking down Kelsey and bringing him back to the Rawlins ranch to be hanged as a horse thief. With a noose around his neck, Kelsey tells the gathered ranchers that, on a retaliatory raid against the Kiowa led by himself and Will Zachary, he found a baby and was about to kill it when Will, sick of all the killing, intervened and took the baby for his own. Kelsey claims that his own son was captured by the Kiowa and demanded that Will return Rachel in exchange for his son, but Will refused. Ben intervenes and tells the gathered group the story he knows - that Kelsey's son was actually killed in the fighting, but that Kelsey refused to believe it, inventing the story as justification for vengeance against the Zacharys. Kelsey followed them from town to town, poisoning the minds of people wherever they moved. Mattilda, driven to the edge by Kelsey's rant and by the continued arguing over the truth, strikes the horse Kelsey is on, causing him to be hanged. This convinces Zeb that Kelsey was telling the truth; he and all of the ranchers turn their backs on the Zacharys. Back at their own homestead, Mattilda admits to her family that Will had taken the Kiowa baby and brought it to her to replace an infant daughter they had just lost. Cash, unable to deal with his sister being a "red-hide nigger", abandons the family. The Kiowa return in force, demanding Rachel, who tries to save her family by going over to the Kiowa. To stop her from doing so, Ben deliberately breaks the truce by ordering Andy to kill a Kiowa, forcing a fight to the finish. Mattilda is killed during the fighting that follows. Just as the family, almost out of ammunition, is about to be overwhelmed, Cash arrives and turns the tide. Rachel, protecting a wounded Andy and aware that Ben loves her, is confronted by Lost Bird, but kills him and thus chooses sides once and for all.
The film was the final film of Hecht-Hill-Lancaster with the film's projected budget of $3 million expanding to $5.5 million. The original screenwriter JP Miller was replaced by Ben Maddow, the original director Delbert Mann was replaced by John Huston, and plans for Richard Burton in the role that eventually went to Audie Murphy were stopped when Burton demanded equal billing with Burt Lancaster, which Lancaster refused. Production was suspended for several months in 1959 after Hepburn broke her back when she fell off a horse while rehearsing a scene. Although she eventually recovered, the accident was blamed for a subsequent miscarriage Hepburn suffered. According to several published biographies of Hepburn, she blamed herself for the accident and subsequently all but disowned the film, although she did complete it when she was well enough to return to work. Hepburn took the next year off work in order to successfully have a child, and returned to the screen with Breakfast at Tiffany's. In addition, Huston was constantly battling with Hecht-Hill-Lancaster, which was financing the movie. Hecht-Hill-Lancaster wanted a more commercial and less controversial film, while Huston wanted to make a statement about racism in America. The result is that neither got exactly what they wanted. Huston's cinematographer of choice Oswald Morris was unavailable to do the film, which led Huston to not talk to him for several years. John Saxon had signed a three picture deal with HHL. The name "Lost Bird" is applied by some Plains Indian tribes to Native children adopted by Anglos. It was popularized by Zintkala Nuni, a HunkpapaLakotah survivor of the Wounded Knee Massacre, taken by Leonard Wright Colby and raised by his wife Clara Bewick Colby, whose widely circulated feminist newspaper The Woman's Tribune carried a column on Zintkala for many years. The Lost Bird Society helps to reunite these adopted children with their birth families.
