The three Mesquiteers try to recover the gold stolen by a gang in its effort to ruin the banker/mayor who ordered them to leave town.

Expelled from his lieutenancy in the Marine Corps, Bill Traylor reenlists as a private. His unit is sent to a Latin American country where a rebel leader called The Torch promotes insurrection. There Traylor encounters again Captain Benton, the man responsible for his disgrace and his rival for the love of a girl.

A Treasury agent gains the trust of a mob gunman while working under cover to smash a crime syndicate.

When Professor Marsh disappears while searching for the lost city of Lukachukai, his daughter enlists the help of the Three Mesquiteers.

Gangster Chandler and his accomplice Tracy arrive at a dude ranch. Cowboy Kentucky arrives at the same time. When Tracy double-crosses his boss and has the stage robbed, Kentucky finds the outlaws and brings them in. Tracy frames him for the murder of the driver but his pal Cactus gets him out of jail. He returns just as Chandler shoots Tracy and Kentucky finds himself arrested for another murder.

Re-edited feature version of serial The Phantom Empire (1935). Singer Gene Autry discovers a race of advanced humans living beneath the earth.

Crash Corrigan, a recent graduate of Annapolis, and Diana, a go-getting reporter, join Professor Norton for a search for the source of a string of earthquakes, Atlantis. They ride Prof. Norton's rocket submarine searching the sea and little Billy Norton, the professor's son stows away, of course. When they find Atlantis they are caught in a war between peaceful Atlanteans, note their white capes, and war-monging Atlanteans, note their black capes. After many harrowing moments for Crash, Diana, Prof. Norton and Billy, they barely get away with their lives when they escape a tower of Atlantis raised to the surface for the sole purpose of dominating or destroying the Earth (Which one depends on the compliance of the upper world dwellers.)