Secret Service Major Steel (Joseph W. Girard), is one of the few men in America aware of the fact that Captain Albright (Dave O'Brien) is also Captain Midnight, daring masked aviator dedicated to fighting gangsters and enemies of America. When murderous bombing attacks are made on West Coast munitions plants, Steel sends for Albright and asks him to track down the mysterious Ivan Shark (James Craven), the foreign agent mastermind behind the attacks. Shark has learned about an ingenious range finder, invented by John Edwards (Bryant Washburn, and makes plans to obtain a model of the invention. Edwards instructs his daughter, Joyce (Dorothy Short), to bring the model to Albright for safekeeping in his mountain laboratory. Shark takes Edwards prisoner by Albright assures Joyce that her father will be saved and an end put to Shark's reign of terror. Dressing as Captain Midnight and enlisting the aid of his friends, Chuck (Sam Edwards) and Ichabod Mudd (Guy Wilkerson), Captain Midnight delivers on his promises fourteen chapters later.
Ken Williams is determined to discover the identity of the mysterious Rattler, who preys upon railroads and transportation companies like that owned by Jane Corwin. The Rattler is especially difficult to catch because of his skill at disguising himself as other people.
White Eagle was raised by Indians after his father, a US army officer, was killed in an Indian raid. He believes that the Indians and the white settlers can live together and works towards that goal, but a gang leader who has his own reasons for not wanting peace between the two groups sets out to stir up as much trouble between them as he can.
Former combat cameraman Mike Kovac is now a freelance photographer in New York City, specializing in difficult and dangerous assignments where he can get the kinds of pictures that other photographers can't, or won't take. He sometimes gets help, often reluctantly, from his contact in the police department, Lt. Donovan, and advice from his immigrant father Anton.
Highlights the personal and professional lives of a group of doctors and surgeons headed by Dr. Konrad Styner. One of the first medical shows on TV that paid strict attention to detail, and heralded at the time for its sometimes unflinching look at the operations and medical procedures performed by doctors.