Alan Armstrong, aka Spy Smasher, battles a Nazi villain known as The Mask, who heads a gang of saboteurs determined to spread destruction across America.

The chapter-crunched version of this 196 minutes, 12-episode serial from Republic finds Canada being bombed mercilessly by a mysterious-enemy plane (shaped like a boomerang) called the Falcon, under the supervision of Admiral Yamata, Count Baroni and Marshal von Horst, chiefs of the Axis Fifth Column in Canada. No one can identify the plane until American inventor, Professor Marshall Brent, and his daughter Carol arrive with a new type of airplane detector. This poses a threat to the Axis chiefs in preparing western Canada for an invasion and they have him kidnapped by local Quisling Gil Harper. RCMP Sergeant Tom King attempts to rescue Brent, but the inventor is killed when a plane in which he is held captive crashes into a riverboat. Carol, determined to carry on her father's work and with King's aid, manages to prevent the enemy agents from capturing the detector, and destroys the device (many chapters later) when the agents make a last desperate attack on the cabin where it is hidden. She is captured and taken to the crater of a volcano, where the ring makes its headquarters.

An American secret agent travels to Africa to infiltrate a Nazi spy ring.

Girl looking for father who disappeared years before in a jungle, finds herself battling greedy civilized people and savages alike.

A mad doctor named Zanoff uses a drug to bring himself back from the dead after his execution in prison. Dick Tracy sets out to capture Zanoff before he can put his criminal gang back together again.

Western settlers are being driven off their homesteads and ranches by a combination of Indian raids and attacks by bands of mysterious outlaws. The government sends out famed Indian scout Kit Carson and army officer David Brent to investigate, and Carson discovers that a villain named Pegleg controls an outlaw gang called the Black Raiders, and is using them and the Indians to drive out the settlers so he can establish his own empire. He determines to set a trap to expose the identity of Pegleg while avoiding traps and ambushes that Pegleg is setting for him.

Filmed in the Sierra Nevada mountains near Sonora, California, this Universal serial is Universal's 40th sound-era serial. Eagle Scout Bruce Scott, leader of Martinsville Troop Number One, and his pack sets off in search of lost treasure and finds adventure.

Dick Tracy battles spies and saboteurs in his efforts to bring to justice the Stark gang, a criminal family led by the vicious Pa Stark.