Jay Grobart, an outlaw, is married to Cat Dancing, Sarah Miles. After Cat is raped and murdered, Grobart kills the man responsible and is arrested. Upon his release, he teams up with Dawes, Jack Warden, Charlie, Jay Varela, and Billy, Bo Hopkins, to pull off a daring train robbery, and soon he is back on the run from the law.
On the run, Grobart and his partners come across Catherine, a woman escaping her abusive husband, Crocker, George Hamilton. Catherine is abducted by Dawes and Billy, but Grobart protects her from them. Lapchance, a veteran railroad detective with a posse, is on their trail for the train robbery, Lee J. Cobb. Accompanying the posse is Catherine's husband Willard Crocker, an arrogant millionaire, who is obsessed with retrieving his wife, though he knows that she does not love him. As Grobart and Catherine get to know each other, they find themselves falling in love, and despite his criminal past, she admires him for avenging the death of the woman he loved.
Dawes beats Billy, causing internal injuries that should soon kill him. Grobart leaves the others at an old cabin for a day. A few marauding Indians attack the cabin, killing Billy and Charlie, while Dawes runs off with some of the money. Grobart returns and kills the marauders in an intense battle. Catherine and he continue their journey. Catherine admits her feelings for Grobart, and they make love. Dawes finds them, rapes Catherine, and plans to kill Grobart for the remaining money, but is killed by Grobart.
Grobart and Catherine travel to the Shoshone village where Grobart lived with Cat Dancing and their children — their very young daughter and their young son, Dream Speaker, Sutero García Jr. — who now live with Cat Dancing's brother, Iron Knife, Larry Littlebird. He discovers that his children have bonded with the Shoshone and wish to remain in the village. Grobart is also revealed to have pushed his son aside and strangled Cat Dancing, thinking that she had chosen to sleep with the man who, in fact, had raped her. Grobart leaves Catherine and the railroad money at the village and departs, not wanting to place her in further danger.
The posse arrives at the village and retrieves the money. Crocker insists on pursuing Grobart to kill him. The posse spends the night at the village. That evening, Catherine and Dream Speaker leave to find Grobart, with Dream Speaker guiding her to a cave in the hills where Grobart is camped out. Grobart bids his son farewell and reunites with Catherine. The following morning, as they prepare to leave, Crocker arrives and shoots Grobart from the tree line. Grobart is wounded and Catherine rushes to his aid. Catherine grabs Grobart's pistol from his holster and shoots Crocker dead as he charges them. Lapchance orders his men to put Crocker's body on a pack horse, and having already retrieved the railroad's money, leaves Crocker's horse for Grobart. Grobart pulls himself to his feet and embraces Catherine.
