U.S. Marshals Nevada Jack McKenzie and Sandy Hopkins ride into Big Piney Basin at the request of Ann Jordan, daughter of a rancher who has been killed and whose cattle have been rustled. At Ann's home, they find Ted Connors, the only surviving member of the Connors brothers, the other two having been killed the previous night. Nevada rides into town and discovers it is run by Matson and Judge Kelbro and that it was Matson's gang that killed the Connors and Ann's father. Matson believes that Ted, who can identify some of the gang, is dead but sends his henchmen out to investigate. Sandy, working as a swamper in the poolroom, overhears a plot to rustle the remaining cattle, and rides out to warn Nevada and Ann. Nevada and Sandy round up the gang, Matson and Kelbro are turned over to the authorities, and Ted and Ann are planning their marriage as Nevada and Sandy ride off to new adventures.