When he is told that he is to spend three more years as a tailgunner, goofball GI Herbert Pumice thinks that a promotion--which he has little to no chance of getting--will get him out of the job he hates. He asks his girlfriend Sally, who owns the base café, for help. She goes to the base commander, Col. Baker--who she knows has a crush on her--to help out Herbert. Col. Baker schedules a promotion hearing for Herbert that Friday. He naturally fails it miserably, and then learns that Col. Baker is going out on a date with Sally. Meanwhile, the base military intelligence officer discovers that Herbert is a dead-ringer for the head of a spy ring intending to sabotage a new automated plane, and gets Herbert assigned to infiltrate the gang. Complications ensue.

"The saddest sack in the sky!"