Wildcat riggers risk their lives in the pursuit of oil. Their jobs get even more dangerous when ruthless oil baron J.C. Anderson sets his sights on their territory. When longtime driller Dan O'Reilly falls to his death from a well tower sabotaged by Anderson's strong-arm thugs, his teenage son 'Fishtail' inherits the property and the troubles that come with it. With the help of his geologist pal, Hank Langford, the boy fights to bring in a gusher before the deed to the well-site expires.
Larry Baker is a young fireman whose daring exploits have led him to receiving a lot of newspaper publicity which goes to his head. His sweetheart, Mary O'Connor, and fire-department friends begin to shun him as they think he is just a publicity hound. But a daring rescue of Mary and her younger brother, Mickey, from a blazing inferno shows him to be more than just a publicity-chaser and, now, a real hero to all.
Sheriff John Higgins quits and goes into prospecting after he thinks he has killed his best friend in shooting it out with robbers. He encounters his dead buddy's sister and helps her run her ranch. Then she finds out about his past.
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.
When John Mason's father is killed, John is wounded. Attracted to his nurse Alice, a conflict arises between him and his friend Ben who plans to marry Alice. John later finds the killer of his father but goes to face him not knowing Ben has removed the bullets from his gun.
Rodeo star John Scott and his gambler friend Kansas Charlie are wrongly accused of armed robbery. They leave town as fast as they can to go looking for their own suspects in Poker City.
The son of Sheriff Clay Hartley, of the frontier town Elder, has gotten into bad company and hangs out with an outlaw gang in which, Collins, owner of the Golden Rule Saloon, is the secret head. Sheriff Hartley suspects him, but has been unable to gather the needed evidence. Collins instructs his gang, including young Hartley, to hold up the stagecoach on its return trip from Missionary Flats and take the cargo of gold dust it is carrying. Sheriff Hartley is notified of the planned holdup by one of his deputies who has been spying on Collins, and organizes a posse. A deputy-sheriff is killed in the ensuing gunfight between the lawmen and the outlaws, but Deputy Joe Larkin, pursues and captures Clay Hartley Jr. The latter is quickly tried and convicted of the killing of the deputy, and sentenced to be hung. Sheriff Hartley has only a few hours to prove his son was not the killer. He enlists the aid of Collins' step-daughter, Joan, who is in love with Hartley's son.
Grant hides stolen money in the luggage of Bonnie Shea who is moving west. Later when he and his men arrive to retrieve the money, they also kidnap Bonnie. This sends Reasonin' Bates and his cowhands on their horses after the gangsters in their cars.
On the mystic island of Lemuria, the cult of Ubasti seek the Egyptian Princess Nadji to sacrifice so that their goddess Ossana, whose soul resides in Nadji's body, may be resurrected by Black Magic. Nadji is located in the Far East port of Suva, but shielded by the White Magical powers of Frank Chandler, an American raised by Eastern mystics who is also known as Chandu. When Chandu takes a voyage alone, however, the evil Voice of Ubasti is able to magically spirit her to Lemuria, where Black Magic reigns supreme. Chandu sets out in pursuit with his sister Dorothy, niece Betty and nephew Bob; but, shipwrecked on the magic island, Chandu finds his family also held prisoner for sacrifice while he is plunged into an endless maze of caverns beneath the evil temple, where both his mortal and magical strength seem rendered useless.
Chris Morrell, the guardian of half-Indian girl Nina, is helping her find her missing white father. so she can cash in on her late mother's oil lease. Outlaw Sam Black is after the girl and her father as well. Besides dealing with the Black gang, Morrell has to find another robber, Jim Moore, who switches clothes with him after he finds Chris unconscious from a fight with Sam Black. Along the way, he meets a lady who's the sister of Jim Moore, another bad hombre who's in cahoots with Jim Moore, and an old friend who takes in Nina and helps Chris locate Nina's father and fight off the various desperadoes
Tobin is after the bandit Zanti who killed his parents. He finds him just as Zanti is about to kill Dusty and kidnap Ruby. Saving the two, he goes after Zanti. He catches him but Zanti escapes the Sheriff's handcuff's and this time Tobin has to chase him into the desert.
Henry Jethrow is after the Wilson ranch. He has George Wilson unknowningly sign a note for the ranch, has him killed, and then presents the note. The Pinto Kid, investigating cattle rustlers, accidentally drops his glove at the murder scene and now has a price on his head. He has Beth Wilson turn him and use the reward money to reclaim the note. Now he has to escape jail and find the real killers.
Two military pilots are close friends, and share in a lot of hazardous missions while engaging in a series of good-natured romantic rivalries. But when one of the pilots loses a girl he really cared for, he cannot forgive his friend. Soon afterwards, they must work together on their most dangerous mission yet.
After Fred von Bergen, a German immigrant in America, is forced from his job by anti-German hysteria before the first world war, he and his friend Bob Wilson leave America and join the German air force. There, both men fall in love with ambulance driver Alida Hoffman. When America enters the war, Bob is caught between loyalty to his home country and the threat of execution for desertion and treason to Germany. It remains for his friend Fred to extricate him from the dilemma - but at what cost?
Chandu consults his crystal ball and sees that Nadji, Princess of Egypt, is in danger. She is about to be sacrificed by the black magic cult of Ubasti. Headed for the magic island of Lemuria, he is shipwrecked , washed ashore and captured. He becomes invisible, escapes and after numerous detours is able to rescue the princess.
An Easterner Inherits a cattle ranch, only to discover that thousands of cattle have been stolen. He secretly signs on as a hired hand at his own ranch to discover who's stealing them.