This spaghetti western presents a fictitious version of the often filmed legend of Pat Garrett and Billy the Kid. Billy becomes innocently an outlaw while protecting his mother, but then turns into a trigger happy killer. When he falls in love he tries with the help of Pat Garrett, a fatherly friend, to change back. However, circumstances force Billy to become violent again and it is Garrett who is credited with the killing.
Billy, after shooting down land baron William Donovan's henchmen for killing Billy's boss, is hunted down and captured by his friend, Sheriff Pat Garrett. He escapes and is on his way to Mexico when Garrett, recapturing him, must decide whether to bring him in or to let him go.
Billy the Kid and his pal Jeff help their friend Fuzzy Jones escape from jail, and the trio heads for Paradise Valley, where they find the Paradise Land Development Company, ran by Matt Brawley and Jack Saunders, is somewhat less than honest in their dealings with the homesteaders. They devise a plan to cause a split between Brawley and Saunders.
Knowing the Army is arriving to establish a post. Doc Hagan and his gang and the crooked Sheriff are trying to drive the ranchers off the land. When the gang wound a rancher, the Doc finishes him off with his needle. Running from the law again, Billy and his pals arrive and take up the ranchers fight. But when Billy's pal Jeff is wounded, Fuzzy unknowningly takes him to Doc Hagan.
When Sheriff Hanley sends for Billy and his pals, they arrive to find him murdered and Ed Slade temporary Sheriff.
Billy the Kid has been wrongfully arrested for robbing a train. In order to prove his innocence, the Kid breaks out of jail and hits the trail to search for the real robbers. Along the way, he discovers that an outlaw band has been impersonating upstanding ranchers.
Billy, Fuzzy, and Jeff are on the run from the law again. This time they travel to a new town where Fuzzy is made Marshal. But Hardy and his outlaw gang control the town and none of the previous Marshals survived for very long.
Escaping from the law once again, Billy, Fuzzy, and Jeff ride to the ranch of Jeff's uncle only to find another family living their. They soon learn of Cobb Allen's scheme where he sells a ranch, makes sure the rancher can't pay off his note, kicks him out, and resells the ranch. But Billy has a plan to recover the ranchers' money and he sends Fuzzy to town with a fake map to a gold treasure.
Falsely accused of murder, Billy is able to escape thanks to his pals. Once in Santa Fe, he meets once again the man who lied during the trial.
Tom Carter, his wife and his son Billy, live quietly on the family farm until a dispute arises between him and his rich neighbour John Price who organizes a punitive expedition against Carter. Billy is sent to Littleton by his father and when he returns he finds the house burnt down, his father killed and his mother injured. The cautious sheriff prefers to conclude to an accident despite Billy's insistance. So Billy decides to take the law into his own hands...
Williams is out to stop Ellen Goreham from completing her road that is under construction and is using a man to impersonate Billy the Kid. When Billy sees the wanted posters and learns of the murders he supposedly committed, he sets out to find the imposter. His sidekick Fuzzy is there to help him but his friend Jeff, now a Marshal, is also after him.
Western gunfighter Billy Kid decides to embark upon a new life and, accompanied by his sister, sets off on the long journey to his ranch. The journey is fraught with danger as Billy is attacked by both gunmen and lawmen.