In the town of San Lorenzo, Ed Walton reports twelve more of his cattle stolen, while another rancher, Don Rafael Ortega, sends a message to Prescott, Arizona, that San Lorenzo needs a marshal. On the stagecoach, Red Larson is brought in wounded after being shot by a stranger on a white horse. When a stranger, Tim Hamlin, arrives in town, the saloon keeper, Bonner, assumes Tim is responsible for Red's injury and warns him that Red has many friends. Tim shoots Bonner's gun from his hand and backs out of the saloon. Ed comes to Tim's aid and Tim explains that he is not Captain Willoughby, the new marshal, but a cowpoke looking for a job as a foreman. Ed suggests Tim try the Ortega ranch, and after Tim meets Rafael's daughter Dolores, he agrees to help the rancher out. Bonner holds a note on the Ortega ranch, which Rafael cannot pay because his cattle are being stolen. Tim is slightly hurt when he stops a raid, and Ed, Bonner's secret leader, is surprised to find Tim alive when he arrives to propose to Dolores. Meanwhile, Dr. Haley warns Tim that Ed is not the man he seems. A vigilante group forms and takes Tim prisoner, but he escapes in time to see the stagecoach arrive, carrying a wounded Rafael. Tim is suspected of the crime when his horse is found sweaty from a hard ride, and escapes a crowd ready to lynch him by pulling a gun. Meanwhile, Ed tells Rafael that he will buy the note from Bonner if Dolores will agree to marry him, and she does. The new marshal, Willoughby, arrests Tim and leaves him in Bonner's care, but Tim escapes and forces Bonner to open the safe, which holds Rafael's money. The men fight, and hearing the scuffle, Ed's men come to Bonner's rescue. With all the crooks in one place, Willoughby places them all under arrest and tells Tim that his incarceration was a trick to capture the rustlers. Then Willoughby announces that the law is in San Lorenzo to stay, and Tim is united with Dolores.