Popeye hears a sailor tell a story about an old sailor who looks just like him and who's marooned on a desert island. He sets sail to see if the old man is his long-lost father, Poopdeck Pappy. When Popeye lands on the island, Poopdeck doesn't recognize his son, and he even sends his pet gorilla and octopus to get rid of Popeye. Popeye does away with both of them. Popeye cannot convince Poopdeck that he's his son. The Monster of the Sea attacks them, and Poopdeck zips out, leaving Popeye to confront the monster. As Popeye's about to eat spinach, the can is thrown from his hand by the monster. The can rolls into the scene where Poopdeck is hiding. Poopdeck realizes that Popeye really is his son. He eats the spinach and knocks the monster back into the sea. There's a happy father-and-son reunion at the fade.