Before he arrives home, however, the train is ambushed by a group of miscreants who promptly free the prisoner Butch Cavendish before setting the train on a collision course. His life is saved, in part, by another prisoner aboard the train, the Comanche outcast Tonto, who failed in his attempt to kill Butch thanks to John's intervention. With his brother Dan's assistance, John places Tonto in prison to await trial and accompanies his brother on a quest to track down the band of outlaws led by Butch. But with a traitor in their midst, the Reids' company are ambushed en route and all seven of them are killed. At the bequest of a white spirit horse, however, Tonto later learns that John has been chosen as a "spirit walker" (a man who cannot be killed in battle) to help him in his quest to destroy Butch for his crimes against the Comanche tribe.