When Captain Kidd is reprieved from the gallows by a greedy nobelman who wants to know the location of his buried treasure, he sets off across the seven seas with faithful slave girl Eva Gabor in tow.

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.

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.

In this short, a modern-day promoter tries to sell a man the idea of searching for Captain Kidd's buried treasure, claiming he has the original map. A flashback reveals that Kidd was known to be a pirate and also to have had a commission from William III at one time, which instructed him to act as a unit of the British Navy. What became of the fabulous treasure Kidd took from the ship "Kedah Merchant".

The story of this film begins with the ominous day on which Lord Bellomont gave William Kidd a commission to rid the seas of pirates. Instead of complying with Lord Bellomont's desires, Kidd immediately commenced a series of piratical attacks at first on French and Spanish vessels and later on ships of all nationalities indiscriminately.