Kosoma, Indian Territory. The outlaw Darby brothers have been sentenced to hang until dead. Witnessing the execution are Amelia Darby, sister of the condemned men, as well as U. S. Deputy Marshal Sam Trusty Dawson and Judge Gordon Hadesworth. After justice is served, Trusty hits the trail, escorting the judge – and begrudgingly, Amelia – back to Oklahoma. Ambushed en route, the judge is murdered and Amelia vanishes, leaving Trusty to believe she led them into a trap for revenge.