Ten years after the Civil War has ended, the Governor of Texas asks Leander McNelly to form a company of Rangers to help uphold the law along the Mexican border. With a few veterans of the war, most of the recruits are young men who have little or no experience with guns or policing crime.
An undercover Texas Ranger runs into trouble when he learns that the murderer he's trailing has a twin brother.
Having fled to Mexico from the U.S. many years ago for killing his father's murderer, Martin Brady travels to Texas to broker an arms deal for his Mexican boss, strongman Governor Cipriano Castro. Brady breaks a leg and while recuperating in Texas the gun shipment is stolen. Complicating matters further the wife of local army major Colton has designs on him, and the local Texas Ranger captain makes him a generous offer to come back to the states and join his outfit. After killing a man in self-defense, Brady slips back over the border and confronts Castro who is not only unhappy that Brady has lost his gun shipment but is about to join forces with Colton to battle the local raiding Apache Indians.
John Wyatt is a government agent sent to smash a counterfeiting operation near the Mexican border. Joining Doc Carter's medicine show they arrive in the town where Curly Joe, who once framed Carter, resides.
Sayres and his outlaw gang operate out of a town just across the border and out of the jurisdiction of the Texas Rangers. Ranger Bob Allen is sent across the border where he poses as an outlaw hoping to lure the gang back into Texas. He gets into Sayres' gang displacing the gang boss but the disgruntled ex-boss is able to expose the hoax and Bob is made a prisoner.
A Texas Ranger and a ruthless narcotics kingpin - they were childhood friends, now they are adversaries...
With thousands of cattle being rustled from White Sage ranch the 1930's Texas Rangers are called in. They manage to get one of their agents into the gang by making them think he is the Pecos Kid on the lam.
Cal Stanley goes undercover as a beef buyer in order to catch the gang responsible for stealing the area's cattle.
Texas Ranger Buck Dunne is assigned to round up a gang of bank robbers. The leader of the gang turns out to be the "respectable" Judge Longstreth, making life difficult for Dunne inasmuch as he's in love with Longstreth's niece Barbara.
A Pinkerton agent masquerades as a criminal in order to infiltrate a gang of counterfeiters that is using wealthy widow Lucy Randall as a front. Arriving at the gang's hideout the Dawson ranch, Red discovers that the counterfeiting ring is headed by Mrs. Randall's attorney J. Richard Spencer and Dawson himself.
The Texas Rangers round up rustlers by masquerading as the same. Trouble ensues when while in disguise one of the Rangers is accused of a killing.