The Mysterious Rider

After her stagecoach is ambushed, a woman is tasked with holding a dangerous outlaw captive and must survive the day when the bandit’s gang tries to free him.

The first of a long-running series of Monogram-produced westerns starring Johnny Mack Brown and Raymond Hatton that replaced the Rough Riders series following the death of Buck Jones in the Boston night club fire. Though the next three years featured Brown (as Nevada Jack McKenzie) and Hatton (in his Sandy Hopkins role from the Rough Riders series) as undercover marshals in some form or another, this initial entry had Brown as a lone rider seeking vengeance and he and Hatton's characters were unknown to each other through most of the film. Hopkins offer McKenzie a marshal's job at the end of the film, which the Brown character declined and rode off alone on his quest. This quest didn't take long as by the next film in the series Nevada Jack McKenzie was a full-fledged U. S. Marshal.

Tom Evans (Jon Dawson), nephew of U.S. Marshal Sandy Hopkins (Raymond Hatton), has just trailed his cattle to Yucca City, where he intends to sell to Ben Crowley (Harry Woods), owner of practically everything in town.Tom loses his money in a crooked game ran by Crowley. "Nevada Jack" McKenzie (Johnny Mack Brown), a U.S. Marshal working undercover, watches the game and secures one of the "fixed" decks of cards. Later, Tom discovers Crowley's men rustling his cattle and is shot. Nevada finds him severely wounded and hides him with Jeff Lewis (Sam Flint) and his daughter Mary (Ellen Hall). Sandy, posing as a dentist, arrives in town after a wire from Nevada. The latter confronts Crowley with the crooked deck and also with the fact that Tom is still alive, and demands a partnership from Crowley. When Crowley learns that Lewis is hiding Tom, he decides to have both Tom and Nevada killed.

On her b-day, settler's daughter Apanatschi receives her father's secret gold mine but greedy neighboring prospectors resort to murder and kidnapping in order to get the gold, forcing the girl and her brother to seek Winnetou's protection.

At the height of the frontier era, a train races through the Rocky Mountains on a classified mission to a remote army post. But one by one the passengers are being murdered, and their only hope is the mysterious John Deakin, who's being transported to face trial for murder.

Carl Beldon has disappeared and the Trail Blazers have been sent to investigate. Arriving in town, they find that 'Honest John' controls everything. He even prints his own money. He also has a gang and they set out to finish off the heroes.

Two jobless Americans convince a prospector to travel to the mountains of Mexico with them in search of gold. But the hostile wilderness, local bandits, and greed all get in the way of their journey.

Stodge City is in the grip of the Rumpo Kid and his gang. Mistaken identity again takes a hand as a 'sanitary engineer' named Marshal P. Knutt is mistaken for a law marshal. Being the conscientious sort, Marshal tries to help the town get rid of Rumpo, and a showdown is inevitable. Marshal has two aids—revenge-seeking Annie Oakley and his sanitary expertise.

Will Kane, the sheriff of a small town in New Mexico, learns a notorious outlaw he put in jail has been freed, and will be arriving on the noon train. Knowing the outlaw and his gang are coming to kill him, Kane is determined to stand his ground, so he attempts to gather a posse from among the local townspeople.

When Sheriff Jake sees a man at the safe and then finds the payroll gone, he trails him. Just as he is about to arrest him, the man saves his life. Still suspicious, he joins up with the man and later they learn that Melgrove, the towns leading citizen, is trying to take over the area's ranches by having his gang stop all incoming supply wagons. With the ranchers about to sell to Melgrove, the two newcomers say they will bring in provisions.

J.D. Cahill is the toughest U.S. Marshal they've got, just the sound of his name makes bad guys stop in their tracks, so when his two young boy's want to get his attention they decide to rob a bank. They end up getting more than they bargained for.