Physicist Ted Hall is recruited to join the Manhattan Project as a teenager and goes to Los Alamos with no idea what he'll be working on. When he learns the true nature of the weapon being designed, he fears the post-war risk of a nuclear holocaust and begins to pass significant information to the Soviet Union.

Petty con artists Slicker Smith and Herbie Brown mistakenly join the Army evading the cops. The cop chasing them winds up as their drill instructor. A rich young man and his former working class chauffeur are not only in the same unit, they're vying for a pretty girl who seems attracted to both.