 In the Nineteenth Century, in the town of Lincoln, New Mexico, the sheriff Pat Garrett (Thomas Mitchell) welcomes his old friend, Doc Holliday (Walter Huston), who has had his horse Red stolen by a stranger while coming to the town. They meet the thieve and realize that the guy is the gunman Billy the Kid (Jack Beutel). Doc becomes friend of Billy, but Pat invites them to leave Lincoln in the afternoon. There is an incident, Pat wounds Billy the Kid, and Doc asks his girlfriend Rio McDonald (Jane Russell) to take care of Billy while he would misguide Pat Garret t and his officers. There is a romance between Billy the Kid and Rio, and when the hit-man is healed, he disputes with Doc the possession of Red and Rio, with Pat Garrett chasing them. On 13 July 1881, this hunting ends in a tragic way.