Popeye serves spinach sandwiches to his nephews during a picnic. They protest, so he tells them a tale from his youth in a Jack‑and‑the‑Beanstalk style scenario: after being paid with a spinach can, a giant spinach stalk sprouts. Popeye climbs it, confronts a giant in a cloud castle, rescues a magical hen, and ends up using spinach to defeat the giant. After finishing the story, the nephews accept their spinach sandwiches.