Phantom Stallion is a 1954 black and white classic set in the Old West. A hard-working but desperate California ranch owner, Mike Reilly (Harry Shannon), is out to discover who has been stealing his prize horses and enlists the help of a couple of former cavalry riders, Rex (Rex Allen) and Slim (Slim Pickens). Rex and Slim have come west as wagon train guides and are looking for work. Mike has yet to realize that right under his nose, his beautiful niece Claire (Carla Balenda) has been working alongside a treacherous foreman Gil (Don Haggerty) to steal away the animals and profit off her uncle. Claire believes that she is the rightful and slighted heiress of the Reilly Ranch and will not hear otherwise. Worse yet, they have been planning Mike's demise all along. Rex and Slim band together to solve a murder and foil the plot before the culprits get away with mayhem.