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.