New York City cop Phil Donlon leaves the force to join the U.S. Olympic team. When he falls for a Marine colonel's daughter he gets kicked off the team. Joining the Marines to win the Colonel's approval many adventures follow.

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.

After being run out of town after town for trying to sell worthless stock, two con artists breeze into the small town of Chesterville, where they find themselves accused of kidnapping a young boy to whom they offered a ride. When that misunderstanding is cleared up, the two conmen hatch a plot to unload all their worthless paper on the gullible citizens of Chesterville.

Hammond is after the Craig ranch and has framed Charlie Craig for murder. Mother Craig brings in the Range Busters. They capture one of Hammond's men and Alibi plans to trick him into a confession as to who the real murderer is. Meanwhile, Denny has overheard Hammond's plans for his next move and he and Crash set out to round up the gang.

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

The stooges apply for job as 'Yard Men' at Scotland Yard, thinking they'll become detectives, but instead wind up as gardeners. When they accidentally see a memo about the theft a famous diamond, the boys decide to go after the crooks. They find the crooks, but Shemp accidentally swallows the diamond which was hidden in a bowl of candy. The bad guys want to cut the diamond out, but the boys foil them with the help of a friendly gorilla.

A white gorilla causes trouble in the deepest heart of Africa. The film uses footage from the silent 1927 serial Perils Of The Jungle.

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.)