After staging a mutiny and commandeering his own ship, famed pirate Barbarossa (John Payne) takes hostage a spirited Spanish noblewoman named Alida (Donna Reed), intending to trade her to her fiancé, Capt. Jose Salcedo (Gerald Mohr), for a handsome ransom. But Barbarossa falls in love with Alida, who meanwhile discovers that the roguish swashbuckler is more honorable than her erstwhile betrothed.