Posing as Diana Prince, Wonder Woman obtains employment as General Darnell's secretary working at the U.S. Military Intelligence Headquarters. She discovers that Eve Brown has been leaking defense secrets to the Nazis and manages to capture a nazi spy named Gross.
Wonder Woman, as Diana Princess, is distraught because she has been acting as Steve Trevor's nurse and he is now healthy and ready to go back to work. He agrees to get her a job as General Darnell's secretary, meaning that she works in the same office as Steve. Steve's secretary, Lila Brown, is jealous of Diana because of her amazing typing and short-hand skills.
Steve learns that a woman in the office is leaking military secrets to Nazi agents. Lila suspects Diana. Meanwhile, General Darnell has tasked Diana with putting together a health report on all 247 female employees at the Headquarters. While testing Lila, she discovers that Lila has a letter that she got from her sister, Eve Brown, containing information about a formula for airplane armor that Steve is supposed to be taking to New York. Lila assures Diana that she will come clean about the letter, but before this happens Diana is caught with the letter and arrested.
As Wonder Woman, Diana escapes and finds Lila, who confesses that she took the letter from her sister, Eve, before Eve could deliver it to a Nazi agent. Eve, it turns out, has fallen for a Nazi spy named Herr Gross, who blackmailed her into betraying the U.S. military. With Lila's help, Wonder Woman tracks down Herr Gross and forces him to reveal the Nazi plan to capture Steve and steal the formula. Afraid that she won't be able to reach Steve in time, she calls upon the Holiday Girls, led by Etta Candy, to help.
Eve, meanwhile, is helping to execute the Nazi plan. She is on Steve's train, headed for New York, and convinces him that there are Nazi agents in Baltimore that he can capture if he gets off there. He does, but Eve leads him into a trap. Before he is captured, though, he drops the formula and Eve, realizing that the Nazis plan to kill her as well as Steve, grabs it and runs away. She comes across the Holiday Girls and they take her into custody.
Meanwhile, Wonder Woman finds the boat that the Nazis are using to transport Steve. She boards and defeats all of the Nazis and frees Steve.
She visits the Holiday Girls only to find that they are punishing Eve by blindfolding her and spanking her. Eve claims that this punishment has enabled her to realize the error of her ways. Back at the military headquarters, Wonder Woman, as Diana once again, is cleared of all charges. To make up for his having Diana arrested, General Darnell agrees not to punish Eve, but to let her enroll in Holiday College instead.