A Nazi spy ring is after a chemical formula that increases the power of ordinary gasoline for U.S. Army aviation use. Two U.S. chemical companies are developing the formula, with each working on half for security purposes. The spies get half the formula and know that either of two chemists, Robert Norton or Tom Fielding, knows the rest. They capture Fielding, through a ruse by gang member Linda Pavlo, and threaten the life of his sister Nancy and his mother if he does not give them the formula. To protect his friend Fielding, who does know the formula and is engaged to Nancy, Tom pretends to know the secret and boards the Dawn Express plane with the spy leader and his gang.
As foreman of a dude ranch, Gene has two problems. One is a guest, the spoiled daughter of a millioniare, and the other is the disgruntled ex-foreman that Gene replaced, now just a ranch hand. Gene eventually gets the daughter straightened out but has to fire the ex-foreman and this leads to trouble when he returns intent on revenge.
Nona Brooks, former member of a stranded theatrical troupe, earns a temporary living singing in a café in Duakwa, British Rhodesia, Africa. The café owner is secretly in league with two foreign agents with a goal of making the natives restless. American explorer Larry Mason leaves for the jungle with his servant, Jeff and a safari. Nona escapes the café into the jungle but is followed by the agents as, unknowing to her, she is carrying a report of the agent's activities. She joins the safari just as all hands are captured by a tribe of natives
The Mesquiteers return to Texas after the Civil War to find Army carpetbaggers fighting the local bushwackers. They quickly learn that Capt. Hawks and his men are the culprits and join up with Morgan and his men.
A scientific expedition happens to discover that gold exists on Tarzan's escarpment. The villainous Medford and Vandermeer kidnap Jane and Boy to extort from Tarzan the location of the gold.
Successful movie director John L. Sullivan, convinced he won't be able to film his ambitious masterpiece until he has suffered, dons a hobo disguise and sets off on a journey, aiming to "know trouble" first-hand. When all he finds is a train ride back to Hollywood and a beautiful blonde companion, he redoubles his efforts, managing to land himself in more trouble than he bargained for when he loses his memory and ends up a prisoner on a chain gang.
To fight a poisonous weed, ranchers are burning their land. Gene is the Inspector brought in and he recommends spraying. The spraying goes well until the Larabee ranch is reached. When Larrabee refuses to allow the equipment on his land, Gene has it sprayed by airplane. Cattle must stay off recently sprayed land and when a Larrabee man shoots down the plane, the crash sends the cattle stampeding toward the newly sprayed land.
An expedition sets out to darkest Africa to find the fabled City of the Dead, and must battle thick jungle, hostile natives, wild animals and a deadly epidemic.
Based on the comic strip by Gene Byrnes, the "Reg'lar Fellers", and one girl-feller, tinker with building a land/water machine, form a kid-band and go on the radio, celebrate a birthday, get involved with gangsters...and reunite a wealthy recluse with her baby granddaughter and estranged daughter-in-law.
Eccentric Cambridge archaeologist Horatio Smith takes a group of British and American archaeology students to pre-war Nazi Germany to help in his excavations. His research is supported by the Nazis, since he professes to be looking for evidence of the Aryan origins of German civilisation. However, he has a secret agenda: to free inmates of the concentration camps.
Roy is a newspaper reporter. He goes to Cheyenne to cover the activities of supposed bad guy Arapahoe Brown. Roy, of course, discovers who the real bad guy is.
It's war time London and the Crazy Gang (Flanagan & Allen, Nervo & Knox, Naughton & Gold) are doing their bit for the war effort by running a fish and chip stall using their platoon's barrage balloon for advertising. Their Sgt Major is not happy about this and orders them to take the balloon down, but a freak heavy wind accidentally carries the gang away to Nazi Germany. They are captured and placed in a detention camp where they meet an elderly prisoner named Jerry, who possess a map for the location of a secret weapon which will win the war! Fortunately Teddy Knox's impersonation of Hitler lands him the spot of pretending to be the Fuhrer at a gala dinner and the gang are allowed out of the camp. However the Nazis have other ideas for their substitute leader.
Muggs is tricked into entering a Civilian Conservation Corps camp by Danny in order to get in shape. Muggs resists and battles with the camp captain and with other campers. He also becomes involved in trying to help one of his friends get out of trouble.
Rightful owner of the kingdom, the Duchess of Zona, is engaged in a power struggle with the evil General Gurko. Edmond, the son of Monte Cristo, dons many disguises to come to the aid of the Duchess.
In 1820 Spain, the son of a California nobleman comes home to find his native land under a villainous dictatorship. On one hand, he plays the useless fop, while on the other, he is the masked avenger Zorro.