Pvt. Snuffy Smith and Sgt. Homer Gatling are responsible for guarding a secret rocket that is being stored at a missile site in the backwoods of rural Tennessee. Once there, Snuffy finds out his cousin Barney Google is one of the project's chief investors. Trouble arrives when Snuffy invites his pen pal to visit, and she turns out to be part of a German spy ring trying to get its hands on the special fuel formula.