Socialite Jean Howard is stirred to patriotism and eager to help the war effort. When she overhears her father, J. R. Howard (an uncredited Paul Harvey), complain that the military has taken all of the salesmen of his oil rig supply company, she volunteers to take their place. J. R. gives in, though he reminds her that she has never worked a day in her life.
On one business trip, Howard arrives at a town where the only available place to sleep is a bungalow reserved for married couples. When she is mistaken for the war bride of a lieutenant, she goes along. To register at the Colonial Auto Court, however, she has to produce her "husband". She persuades a very reluctant Lieutenant Don Mallory to help her out, promising it will only take a few minutes of his day off. The couple become trapped in their masquerade as newlyweds when they run into Don's commanding officer, Colonel Michael Otley, who lives just a few doors down with his wife.
When Howard goes out to see prospective customer Earl "Slim" Clark, he insists on taking her out to dinner to discuss the deal. To maintain appearances, Don goes along. The dinner does not go well. While trying to restrain a drunk acquaintance, Slim accidentally knocks Don out and is himself rendered unconscious by the drunk man.
When they return to the auto court, Don and Jean have to sleep under the same roof on their "wedding night". He gives her the bed and sleeps first in the kitchen, which proves too uncomfortable, so he goes outdoors.
Complications ensue when Otley takes an interest in the couple and insists that Don make Jean the beneficiary of his insurance policy and allot her part of his pay. Don's mother also arrives for an early unexpected visit.
During a dinner party given by the Otleys for the couple, the colonel mentions to Jean the impending court-martial of another lieutenant who lied about being married. Alarmed, she drinks too much sherry to steady her nerves. While drunk, she privately reveals to Don that she has fallen in love with him.
The charade is finally revealed when the colonel and Don's mother meet. Jean's father also joins the festivities. Fortunately, Lucille, a male auto court employee, tells Otley that he did see Don sleep outside, so the colonel does not press charges. Don decides the thing to do is to get married for real, much to Jean's delight.
