In 1699, pirate William Kidd (Charles Laughton) loots and destroys the English galleon ''The Twelve Apostles'' near Madagascar. He and three confederates bury the stolen treasure on a remote island. He then presents himself at the court of William III of England (Henry Daniell) as an honest shipmaster seeking a royal commission as a privateer after striking his colors to a pirate. The king is persuaded by Kidd that the captain of ''The Twelve Apostles'' was that pirate, who has disappeared with its treasure. The King grants the commission.