Poopdeck Pappy is suddenly frightened of a mysterious flute melody that wafts through the air. At first Popeye and Olive cannot hear the haunting melody, but Pappy tells them about when he was a young man, and he was attracted to a young woman, a jewel of the sea, who tried to seduce him but turned out to be Wicked Seahag in disguise. Upon discovering her true identity Pappy fled, and Seahag vowed revenge. Now she has discovered a flute melody that can hypnotize Pappy into her trap, and when Popeye and Olive finally do hear the haunting melody, Pappy becomes hypnotized drawn to the dungeon of a distant castle, where Popeye must enlist the aid of Eugene The Jeep is rescue him.