Billy the Kid, who has been unfairly labeled as a notorious criminal, and his cohorts, Fuzzy Jones and Jeff, are arrested by the Cavalry for various crimes of which they are innocent. When Billy discovers that the commanding lieutenant, Ted Morrison, is his exact double, he holds Ted at gunpoint and steals his uniform. Billy, dressed as Ted, Fuzzy and Jeff emerge from the fort and are shot at by unidentified assailants. Billy's wound is only superficial, and in Ted's coat pocket, he discovers an invitation to the wedding of Mary Todd, Ted's blind and wealthy aunt. Billy suspects that the murder attempt on Ted's life has something to do with Mary's wedding. Unknown to Mary, her long-awaited suitor, George Fremont, whom she has just welcomed into her home, is an impostor working with Mil Crawford, the local justice of the peace, who plans to take over Mary's fortunes once she is married to the impostor. Mil sends his henchman, Turtle, who is also one of Mary's ranch hands, to intercept the stagecoach of the real George Fremont, then murder him and steal his papers. Billy, Fuzzy and Jeff scare off the murderous gang but are too late to save Fremont or his companion, Ted. Billy decides to solve the mystery behind Ted's murder and goes to Mary's house impersonating her nephew. Mil, meanwhile, becomes convinced that Billy is an impostor, and incites a lynch mob to kill him. His plan is foiled by Fuzzy, who dons a stolen cavalry uniform, and identifies Billy as Ted. When Fremont's niece Linda arrives for the wedding, Billy, Fuzzy and Jeff pick her up and tell her that her uncle has been killed and that they are trying to capture the murderers. Linda agrees to help them and interrupts Mary's wedding by identifying Mary's fiancé as an impostor and Mil as a swindler. The gang of outlaws is disarmed by Fuzzy and Jeff, and Billy captures the escaping Mil. With the assurance that Linda will take care of Mary, Billy, Fuzzy and Jeff leave for their next adventure.