Celebrated as supersleuth, Mr. Moto comes out fighting when a brutal boxing match turns into cold-blooded murder! Assisted by detective-in-training Lee Chan, Moto sets out to track down the killer…

A mysterious plague, the Purple Death, ravages the earth. Dr. Zarkov, investigating in his spaceship, finds a ship from planet Mongo seeding the atmosphere with dust. Sure enough, Ming the…

T-Man Brass Bancroft goes undercover in a prison which has a secret counterfeit operation set up in the print shop.

When a singing, song-writing prizefighter is framed for murder and sent to the state pen, his girlfriend sets out to prove his innocence.

A chemical manufacturer is killed just after asking detective James Wong to help him. So detective Wong decides to investigate this as well as two subsequent murders.