Cutthroat pirate William Kidd captures Admiral Blayne’s treasure ship and hides the bounty in a cave. Three years later, Kidd, posing as a respectable merchant captain, offers his services to the King of England. Seeking a social position, Kidd also negotiates for Blayne’s title and lands, provided he can prove Blayne was associated with piracy. Launched upon his royal mission, Kidd is unaware that Blayne’s son Adam is among the crew, determined to clear his father’s name.

Two hapless waiters in a tavern on the Spanish Main play cupid between aristocratic Lady Jane and tavern co-worker Bruce Martindale, but the two bumpkins mix-up a love letter with Captain Kidd’s treasure map of Skull Island, leading to them being kidnapped and taken off to the notorious pirate’s island.

Falsely accused by the corrupt Governor Elden of Charleston of fencing stolen pirate booty, young Davey Crandall and friend Tom Botts buy passage on the ship of local buccaneer Bloodthirsty Ben. They avoid being killed by faking a case of the pox, which causes the panicked captain and crew to desert the ship. The two find themselves alone, and when a lucky cannon shot hits a mast on a British ship, they find themselves mistaken for pirates. They sail to Tortuga, where they recruit such notorious corsairs as Henry Morgan, Captain Kidd, Anne Bonney, and Blackbeard to lay siege to Chaleston and expose the villain Elden.