Captain Midnight and the Secret Squadron track down a dangerous group of diamond smugglers. The assignment is made easier with the help of one of Tut's inventions, an Omni Counter, which reacts to precious gems and metals.

A frantic squadron member asks for Captain Midnight's help. He needs help in exorcising a dangerous ghost. Midnight, Ikky, and Tut set up an electronic perimeter around the Southern mansion that is ""haunted"" by a ghost and discover a foreign agent plotting to use it as a rendezvous site.

The Secret Squadron laboratory is placed at the disposal of a scientist working on a heat-resistant metal needed by the Air Force. The research is stymied by a vindictive scientist who develops a sonic gun and hates the other scientist.

A munitions genius is released from jail and plots revenge against Captain Midnight and the police responsible for his conviction.

Captain Midnight exposes a phony seance racket that preys upon a wealthy society women who is also the wife of a famous physicist. The professor has invented a device to harness the power of the sun. The seance racket is merely a scheme to obtain the Professor's invention.

Captain Midnight and Ikky go to Mexico to find an enemy radio station. The last intercepted message from the station referred to a shipment of fissionable materials that may prove a danger to the United States.

A famous scientist who is working on a new metal that may be the key to space travel is kidnapped. In the middle of a desert, Captain Midnight locates the scientist in a state of frozen animation. In order to save the scientist, Captain Midnight must survive a nuclear test at ground zero.

A banker disappers with a significant amount of money. Captain Midnight and Ikky trace the man to a small Pacific Island where he is recovering from exhaustion. The arrival of three greedy thugs on the island complicates Captain Midnight attempt to help the banker clear his name and return to his family.