In 1849, Joaquin Murietta, son of a wealthy Spanish grandee, has a bitter street quarrel with three rough prospectors. He later finds the family home in ruins and his father dying---the result of an attack by the same three men; "Black" Kelly, Ike Mason and Al Goss. Joaquin goes to a mining camp to inform his brother, Juan, of the murder and, on his way, he meets Helen Lake, who has come west to teach in the town school. Determined to get possession of the rich Murietta claim, Kelly, Mason and Goss attack the camp, kill Juan and beat Joaquin into unconsciousness. But even with the Murietta claim in their possession these men do not prosper long. A mysterious bandit, known as "The Black Shadow", continually raids the stage coach which carries shipments of their ore. Captain Lake of the United States Army, who is Helen's father, offers a reward of $5,000 for the capture of "The Black Shadow", but Joaquin's disguise is too effective and he eludes capture. He posts a placard in the local saloon threatening Kelly, Mason and Goss with death... and then manages to carry out the threat without committing bloodshed himself; Kelly is inadvertently shot by Goss and Goss also hits Mason while firing wildly at "The Black Shadow." Goss gets his when Joaquin forces him to wear the costume of "The Black Shadow" and is shot down by a mob. Columbia remade this in 1942 as the last entry in the studio's eight-film series starring Bill Elliott and Tex Ritter, with Elliott in the Murietta role and Ritter in a revised version of the "Captain Lake" role, minus the daughter.