The initial adventures of the show involved the title charac­ter, Charles J. ("Jim" or "Red") Albright, who was referred to primarily by his alias "Captain Midnight," as an independent pilot who acted altruistically to fight wrongdoing, along with his ward, Chuck Ramsay, a girl sidekick, Patsy Donovan, and various others, including a mechanic, Ichabod Mudd. His chief adversary was a criminal, Ivan Shark, who led a gang with his daughter Fury, two aides, Fang and Cardo. Stories involved adventures in the western United States, Mexico, and Canada. In 1940, the program changed sponsors and first aired on a national network, Mutual. Ovaltine had previously sponsored Little Orphan Annie, a 1 5-minute adventure serial based on the newspaper comic strip, since 1930. Ovaltine dropped sponsorship of that show in favor of Captain Midnight, possibly because the international tensions of the era required a mature hero in the eyes of the sponsor. The initial program under the new sponsor provided the hero with an "origin" story (he earned the code name Captain Midnight because of an exploit during World War I) and a secret organization to head. For Orf1han Annie, Ovaltine had developed a club (Radio Orphan Annie's Secret Society) and a "Decoder Pin"; and these were concepts carried over to Captain Midnight. The hero headed a paramilitary organization, the Secret Squadron, which was supposedly set up by a high U.S. government official. Its identifying badge was a cipher device, the Code-O­ Graph, which was used, like its Orphan Annie predecessors, to decrypt "secret messages" provided at the close of some episodes, to provide a hint of the next day's broadcast.

     Most of the main characters from the Skelly show were retained, including Chuck Ramsay, Ichabod Mudd, Ivan Shark, Fury Shark, Fang, and Cardo. One exception was that Patsy Donovan was dropped, and a new girl sidekick, Joyce Ryan, was added. The nature of the Secret Squadron, which was supposed to fight sabotage and espionage, enabled the program to have adventures around the world, including the Caribbean, Central and South America, and China, as well as in the United States. New villains were introduced: the Barracuda shortly before the U.S. entry into World War II, and Baron von Karp, Admiral Himakito, and Senor Schrecker during the war. (An interesting sidelight: well before the 1941 Japanese attack, Captain Midnight found plans for Pearl Harbor in The Barracuda's headquarters in Japanese-occupied China.) After the war, the program continued to be set in locales across the world, and the major villain, Ivan Shark, became prominent again.

     The program retained its 15-minute serial format through June of 1949. In September of that year, it changed format to half-hour, complete-in-one-program stories. These alternated with Tom Mix Ralston Straight Shooters, running on Tuesdays and Thursdays, until the middle of December, when it went off the air.

     The first sponsor, Skelly Oil, aimed most of its products to adults-gasoline, bottled gas, and motor oil. The program attracted a fairly large minority of adult listeners, despite its scheduled spot in the middle of the hour devoted to juvenile programs. This audience carried over to Ovaltine sponsorship. As a result, the vocabulary, dialog, and concepts were more mature than those normally found in a children's adventure show.

     One notable aspect of Captain Midnight was that women were not relegated to stereotypical roles of the time. Joyce Ryan, a teenage Secret Squadron member, routinely faced the same dangers as her male counterparts, including going on commando raids and participating in aerial dogfights. Likewise, Fury Shark was as courageous as her father, and scheming. Neither expected special treatment because of their gender. This was reflected in the handbooks that came with the Code-O-Graph premiums, where both genders were encouraged to go after exciting careers.

      A television version of Captain Midnight was aired on CBS ( 1953-57), sponsored by Ovaltine, but it differed significantly from the radio program. When it was rereleased as a syndicated show, the hero's name was changed to Jet Jackson, and the new name was spliced into the sound track.