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.
