US Marshall Piedmont Kelly is looking into a year-old murder after a gold watch with an inscription linking it to a dead rancher, Albert Bourbonette, is discovered by a constable. Intrigued by the first clue in the murder, Kelly's determined to get to the bottom of it.
The watch was found in the pocket of a man killed in a saloon confrontation. Witness descriptions lead Kelly to the two remaining Bourbonette brothers, who may be trying to track down and kill every member of the gang of raiders they think robbed and shot Albert.
When Kelly rides into the small town of Purdy, he finds evidence that the gang is still operating, working out of a nearby ranch that acts as a front for their illegal activities. But he is puzzled by the disappearance of Bourbonette and why they stuck around just long enough to seek out and shoot only one of the gang.