Popeye the sailor man goes to the seaside village of Sweethaven to look for his long-lost father, Poopdeck Pappy. While there, he falls in love with Olive Oyl, who is engaged to the bullying Captain Bluto, who works for a mystery man called the Commodore, collecting taxes. Popeye and Olive find a foundling who can predict the future, and name him Swee'Pea. The baby is kidnapped and taken out to the Commodore's ship, and when Popeye goes to the rescue, he learns that his Pappy is the Commodore. Bluto has tied Pappy up and is using Swee'Pea to help him find the old man's treasure. After Popeye learns the secret of gaining super strength by eating spinach, he and Bluto fight to the finish, the treasure is found, and Bluto ends up swimming out to sea.