Two investigators for a stagecoach company are assigned to find out why the company's stages keep being ambushed. They discover that the culprits are white men disguised as Indians, and they set out to discover who is behind the plot.

The story of a girl who for months was in perpetual peril; on land, on sea, everywhere, Orient, Occident, and the Antipodes.

On the American frontier in the last decades of the 19th century, Billie is a female cowboy who fights a series of bad men in this film serial.

When Pegleg and his Black Raiders threaten the westward expansion of the United States, the government sends Kit Carson and David Brent to straighten things out.

Stock-footage from Republic Pictures' earlier Zorro serials was served up once again in this 12 chapter cliffhanger, this time without the financially strapped studio having to credit Zorro creator Johnston McCulley or pay any royalties. Zorro simply became "Don Daredevil" (Ken Curtis), a foppish Easterner by day turned masked avenger by night. Like his not too distant relative, Don wore his disguise in order to battle nasty Roy Barcroft who, under a forged Spanish land grant, attempts to take over the surrounding ranch land.

The Phantom Rider helps Mary Grayson thwart a plot to steal her land.

Sergeant MacLane of the Mounties investigates the disruptive activities of a bunch of troublemakers.

The mysterious Don Del Oro ("Lord of Gold"), an idol of the Yaqui Indians, plans to take over the gold and become Emperor. Francisco was put in charge of a legion to combat the Yaqui tribe and protect the land, but when attacked Zorro came to his rescue. Francisco's partner recognized Zorro as the hidalgo Don Diego Vega, then ask him to take over the fighting legion as his alter-ego Zorro.

In 1865, Captain Mark Smith of the Confederate Army leads a band of deserters to conquer Texas and rule it as a dictator. In one of his first actions, he captures and assumes the identity of Texas' new Finance Commissioner, Colonel Marcus Jeffries, after having the real man murdered. When a contingent of Texas Rangers enters the territory, Snead, one of Smith's men, leads them into an ambush by Smith's "troopers". The Rangers are apparently wiped out, although one injured survivor is left. The survivor, nursed back to health by Tonto, swears to avenge the massacre and defeat "Colonel Jeffries" and his men.

King of the Candian riding police is up against Japs and Nazis who are about to invade Canada. They just want to clear the way with a new futuristic plane called "The Falcon" first, but that's not gonna happen if Kig has his way.

Constable Ward is assigned to track down a mysterious villain known only as The Leader. Trying to locate a secret gold mine, The Leader pits the Indians against the Mounties, whom he blames for creating trouble.

In the 56th (and next-to-last serial) made by Columbia Pictures, Montana Deputy Dan Lawson, posing as an outlaw called Laramie, goes to the Canadian northwest on the trail of Bart Randall who is wanted for murder and bank robbery in the states. In Canada, Randall is a little more upscale and uses a hydra-plane and a fake totem to over-awe the Indians. Laramie is aided in his search by RCMP Sergeant Gray and by Donna Blane, who is suspected at first of giving information to Randall, but who is actually a Canadian secret agent investigating Randall's gun-trading with the Indians.