Neil MacGowan, owner of the K-B Ranch, sees good on each side of the struggle between the big cattlemen and the little fellows who sometimes put their branding irons on the wrong beef. He refuses to join the Cattlemen's Association when they bring in "cattle detectives" because juries won't bring a guilty verdict against their friends. Within two months, two rustlers have been killed with notes pinned to their chests reading "Cow Thieves Beware." When MacGowan's neighbor, Stuart Lane -- a homesteader who was never a rustler -- meets the same fate, MacGowan is determined to solve the murder. When his investigation endangers the murdered man's daughter, he rides into Rustlers' Gap to bring the murderer to justice. Hostilities continue to rise, with both sides heading towards a showdown. It will take a man of courage stout to stand between the two sides if a bloodbath is to be avoided -- a man like Neal MacGowan.