Marine Sergeant Bob Lansing has just completed a tour of duty in the Pacific and is off to study at the Officer's Academy in Annapolis if he passes the entrance exam. He soon finds out that his younger brother, Jimmy Lansing, just recently made sergeant as well, will also be taking the exam with him. The Lansing brothers are hard working and patriotic military men and both deserve to be accepted into the Academy, but they learn there is only one spot available. As entrance into Annapolis is dependent both on their exam results and their record, they are encouraged by the base colonel to enter into a friendly rivalry for the three weeks on the base prior to the exam. They also enter into a friendly rivalry for the affections of Penelope Hayworth, the admiral's daughter.

A Chicago gang led by Slade carries out an audacious brokerage robbery. Lieutenant Bill Mason takes the case, continuing his friendly-enemy relationship with crime reporter Ann Rogers. One gang member is caught; eventually, others follow. But Mason hasn't a clue to Slade, principally because he's unaware she's a woman.