Young New York reporter Jimmy Lee proposes marriage to Mary Howard, a successful novelist whom he has long loved, but is refused.  Suspicious that she is becoming involved with her married publisher, Rogers Woodruf, Jimmy tells Mary that the ending of her latest book, in which a mistress confronts her lover's devoted wife and receives her blessing, is unbelievable.  Mary dismisses Jimmy's criticism, however, and quietly arranges with her best friend, widow Bridget Drake, to spend the weekend in the country with Woodruf.

After Jimmy deduces Mary and Bridget's plans, he offers to introduce Woodruf to a famous, elusive writer, whose books Woodruf desperately wants to publish, during the weekend.  Later, Jimmy interrupts an intimate moment between Woodruf and Mary when he climbs Mary's balcony and drunkenly calls to her.

Still conniving, Jimmy plays a game of golf in the country with Woodruf's wife Claire and, confident that Woodruf already has left for Bridget's retreat, telephones his publishing company and states that if Woodruf wants to meet with the famous author he must do so immediately, as he is about to leave New York.

While Woodruf scurries back to the city, Jimmy tells Claire about his ill-fated romance and asks her to pretend to be his "date" in order to make Mary jealous.  Amused, the oblivious Claire agrees to the sham and introduces herself to Mary, Bridget and her gigolo boyfriend, Walter Manning, as "Mrs. Claire," Jimmy's cousin. As hoped, Mary and Claire immediately take to each other and, while a storm rages outside, exchange thoughts about life, love and the ending to Mary's novel.  At first, Claire confirms Mary's conjectures that a loving wife could give up her husband if she were convinced that he would be happier with another woman.

Later, as the two women talk in Mary's bedroom, Claire reveals that for years she has been aware of her own husband's affairs and senses that he is yet again involved with another woman.  Claire then confesses that if this woman were to ask her what Mary's protagonist asks of the wife in Mary's novel, she would wish the woman dead and hang on to her husband at all costs.  At that moment, Woodruf bursts into the bedroom calling to Mary, and his relationship to both Mary and Claire is revealed.  Stricken, Claire asks Woodruf to choose between the two of them, but a chagrined Woodruf refuses to comply.  In disgust, Claire tells Mary that she is willing to give up Woodruf after all and prepares to leave the house.

Afterward, Woodruf confesses to Mary that his intentions toward her are not as serious as she has perceived them and tries to make up with his wife. When Claire tells Woodruf that she no longer loves him and leaves, Jimmy counsels his rival to go after his wife and find a way back into her heart.  Then, while a bemused Bridget tries to make sense of the evening's goings-on, Jimmy consoles a heartbroken but wiser Mary with his love-filled jokes.