A mysterious thief has stolen the prosperous Happy Valley's most prized possession: the musical Singing Harp. Can Mickey, Donald, and Goofy find the answer in the irritable Willie the Giant's magnificent castle up in the blue sky?

Donald is shoveling the snow off his walk; Chip 'n' Dale are shoveling their branch. Donald tricks them into shoveling his walk. Angered, they sneak into his house, where he's getting ready to make popcorn. They've never seen this before, but they love it. They stow away in the box, then make off with the bowl of popped corn.

Donald Fauntleroy Duck gets his draft notice and goes in, past all the amazingly enticing recruiting posters, to sign up. First he has to pass the physical. Despite his flat feet, he makes it. Donald wants to fly, but first he has to make it through Sergeant Pete's boot camp. He has a terrible time with close-order drills, and standing...

Pluto is in the infantry guarding a pillbox from saboteurs.

Donald is stuck on KP at an air training base. Sergeant Pete gives him a huge pile of potatoes to peel first, then gives him some tests: close your eyes and touch fingers, pin the tail on the airplane. He finally gets sent aloft, only to discover it's a parachute jump. Eventually, both Donald and Pete end up falling with no chutes and ...