Captain Mary Morley (Paulette Goddard), WAC marital-relations expert, known as “Captain Lonelyhearts”, returns from overseas as escort to some G.I. war brides, and she hopes to patch up the estrangement from Peter Morley (Fred MacMurray), her husband and former law partner. The latter has fallen for beautiful Gloria Fay (Arleen Whelan) and is waiting at the pier with a divorce consent requiring Mary’s signature. Peter, hoping to be more persuasive later, asks her to have dinner with him later at the Ski Club. Jack Lindsay (Macdonald Carey), a client of Peter’s who has been using their apartment mistakes Mary for one of the intended bridesmaids and asks about Gloria. Now that Mary knows about Gloria, she asks Jack to bring Gloria to the Ski Club dinner. Still in love with Peter, Mary refuses to sign the divorce paper and asks Jack to take her home. Mary is ordered to Fort Sheridan and Peter and Jack board her train - Peter still after her signature and Jack also hoping she will sign as he has fallen for her. Jack advises Peter to make himself so repulsive that Mary will be glad to get rid of him. When Mary reaches Chicago, she is met by three WAC officers and Peter, puffing a king-size cigar, who swoops in and scoops her into his arms. Realizing that Peter must want a divorce badly by staging such a performance, Mary finally consents. Later, when Mary and Peter are going through their personal effects, they begin to reminisce and realize their disagreements were over trivial matters. They embrace, leaving Jack and Gloria out in the cold.