Bumbling war correspondent and former Pulitzer Prize-winner Robert "Kit" Kittredge returns to America and is summarily fired by his boss, Norman Mason, when he fails to report that Germany has invaded Russia. Kit then visits his girlfriend, stenographer Christina Hill, where she works in the Washington, D. C. offices of his former newspaper chain. Their reunion is interrupted by Gregory Vanescu, one of Kit's sources, a Romanian who has come to give Kit a big scoop. Before Vanescu can tell his story, however, Nazi spies shoot at him and he flees, leaving a note instructing Kit to send Christina to the Lincoln Memorial at midnight with a red purse and green umbrella. Kit and Christina ask one of Christina's roommates, Sally Branch, to meet them at the memorial with the purse, umbrella and Christina's monogrammed notepad, but that night, Kit drives Christina to the Washington Monument by mistake. When Vanescu sees Sally, he assumes she is Christina and has her transcribe his information concerning German, Italian and Japanese spies who are headquartered in a Washington beauty shop and preparing to bomb the city. Just as Vanescu finishes, the Nazi agents attack and steal the notebook. Meanwhile, Kit, Christina, her three other roommates and Sally's Marine boyfriend, Red, wait for Sally at her apartment. When she finally returns, hysterical, the roommates give her a sedative before she can tell Kit what has happened to the notebook. Soon after, the spies discover that they cannot translate Sally's shorthand, and so sneak into her apartment and smuggle her out in a hamper. After Kit mistakenly helps the spies, Christina realizes what has happened and insists that he call the FBI, but Kit, anxious to get the story and win his job back, only pretends to do so. Instead, he notices the name of a nightclub on the note Vanescu wrote to him earlier and rushes there to investigate. At the club, a gypsy woman tells Kit to visit a private room upstairs in which, unknown to him, the spy Olga and her superior, Otto Fauscheim, lay in wait. In order to deflect Kit's attention from getting his story, Olga pretends to be Vanescu's wife, seduces Kit and claims to need his help locating her missing husband. She leads him to an old mansion, hoping an insane Civil War veteran living there will frighten him off, but Kit blithely confuses the man by playing along with his delusions, and soon after uncovers Vanescu's dead body. Olga then secretly consults Fauscheim, who decides to incapacitate Kit by ruining his reputation. Fauscheim then drugs Kit with a doped cigarette and has him marry a showgirl, Gloria the Glow Girl, while he is passed out. Although all the papers carry the story of Kit's marriage the next morning, Christina realizes that Kit must have been set up, and when he brings her a handkerchief he stole from Olga, she amasses her roommates, who work in various sectors of the government, to trace the perfume on it. Kit then visits Gloria, who agrees to reveal the Axis plan to her new husband and hands him a flower as a clue, but is stabbed by the spies before she can tell her story. Now suspected of the murder, Kit quickly escapes and searches the flower shop Gloria uses for more clues, but is captured by the lead Italian operative, Baldanacco. The next day, Christina discovers that Olga's perfume was purchased at a beauty salon which is owned by the same poeple who own the nightclub. She goes there, hoping to tie the owners to the spy ring, but when she asks for a massage, Olga, who runs the salon, finds her purse and realizes her name matches that on Sally's notebook. Olga then orders the burly masseuse to detain Christina, while in another room in the salon, the kidnapped Kit escapes from his bonds and, disguising himself as a mannequin, sneaks into the showroom in which the Axis contingent are meeting. After hearing their plans to blow up the city, Kit is discovered, but manages to fend off the spies until the roommates, Red and his Marine buddies arrive in search of Christina and barge into the showroom. The whole group subdues the spies, and as the police arrive, Kit kisses Christina while his friends discuss the likelihood of his winning another Pulitzer Prize.