The plot involves the super-hero called "Captain Invincible" (also known as "Legend in Leotards", "The Caped Contender" and "Man of Magnet") who is active during Prohibition, World War II, and afterwards. Once a popular hero to all Americans, he is forced into retirement by McCarthy-style government persecution in the 1950s.

A congressional investigation accuses him of being a communist, citing his red cape and "premature anti-fascism". He is charged with violating U.S. airspace by flying without a proper license, impersonating a military officer, and wearing underwear in public. He disappears from the public eye, moving to Australia and becoming an alcoholic.

Thirty years later, his old nemesis, the super-villain "Mr. Midnight", re-emerges and steals a secret government super-weapon: the hypno-ray. The US government asks Captain Invincible to return, and the story follows his attempts to return to super-heroing and redeem his reputation.