Synopsis: En route to a Wild West show in Cheyenne, Wyo., cowboy star Roy Rogers intervenes when he sees young outlaw Steve Paxton murder a veterinarian who's on his way to tell local rancher H.T. McKenzie that his cattle herd is infected with hoof-and-mouth disease. With the help of grocer Sparrow Biffle and schoolteacher Ruth Shaw, Roy tries to bring Paxton to justice and keep McKenzie from selling the diseased cattle.