Distraught but skillful bounty hunter Lewis Gates, accompanied by his horse and faithful companion Zip, an Australian cattle dog, tracks three armed escaped convicts into Montana's Oxbow Quadrangle, at the persistence of his unforgiving father-in-law, who blames Gates for his daughter's tragic death. Gates sees the convicts but hears shots. Investigating the scene, all Gates finds is a bloody scrap of cloth, "enough blood to paint the sheriff's office," a bloody shotgun shell, and an old-fashioned Indian arrow.