A playwright and his wife search the past for the key to saving their troubled marriage.

On the train to Philadelphia, actress Janet Boothe flirts with celebrated Broadway playwright Bill Blakeley, in whose latest show she is starring, but is gently rebuffed. Later, from his Philadelphia hotel, Bill calls his wife Carolyn and pleads with her to come up for his opening. When Carolyn makes excuses for why she cannot be there, Bill becomes angry and hangs up. He then runs into Janet in the hallway and makes a dinner date with her. Pleased, Janet calls gossip columnist Lucy Lawson at a television station and reports that the Blakeleys are getting divorced. Although she is unable to verify Janet's claim before airtime, Lucy nonetheless announces the Blakeleys' marital rift and writes about it in her newspaper column. Later, Pop, a New York newsstand operator, tells a curious customer about the first time he met Carolyn Parker years before, when Bill was a struggling writer: On New Year's Eve, in Times Square, Bill notices Carolyn as both are buying newspapers from Pop. After Pop informs Bill that Carolyn always buys a Toledo paper, Bill finds Carolyn among the noisy revelers and pretends to be an acquaintance from Toledo. When Bill boldly kisses her at the stroke of midnight, Carolyn becomes upset and pulls away. Bill apologizes and, while walking her to her apartment, admits his deception. Carolyn, in turn, reveals that the Toledo paper is for a neighbor and suggests he call her for a date. In the present, Pop concludes his story, and later, at Ma Stanton's restaurant, Ma, Carolyn's former landlady, tells her cashier about Bill and Carolyn's romance: At her apartment, Ma helps Carolyn, a fashion model from England, prepare for her first date with Bill. After the nervous Carolyn rips the back of her skirt and inadvertently exposes the tear to Bill, Ma rushes her into the bedroom. Bill then sneaks some food from Carolyn's kitchen and, once alone with her, makes annoying comments about her feminine decor. In retaliation, Carolyn boasts that she recently entertained a man named Timmy, and is chagrined when neighbor Mrs. Wallace comes to her door and asks her to baby-sit her young son, Timmy. Back in the present, the Blakeleys' old friends, Happy and Dolly Murray, discuss Lawson's column and recall the first time they all dined together: At the Murrays' apartment, Dolly, a fellow model, tells Carolyn in private that the jobless, broke Bill is not a good prospect. At first, Carolyn refuses to accept Dolly's assessment, but when she sees him join Happy's poker game, she has second thoughts. Angry at Bill for gambling, Carolyn resolves to break with him, but the next morning when she and Dolly run into him at an automat, she is unable to say no to a date. Back in the present, Happy, a reporter, is called to his office and takes his good friend Joe's cab to work. While driving, Joe remembers some of his encounters with the Blakeleys: Joe drives an elated Bill home after he has received his first $250 payment for writing. Bill presents Carolyn with the money and announces that his play will soon be mounted. The modest production is a flop, however, and in the back of Joe's cab, a despondent Bill informs Carolyn that he is quitting. Carolyn suggests that they form a "partnership" instead, and Bill accepts Carolyn's proposal with a kiss. Months later, Bill, tired of living off Carolyn's modeling wages, is just about to move out and look for a regular job when he receives a call from Venus Motion Pictures, offering to buy the screen rights to his play. When Carolyn returns home from work, she is surprised to find Bill sitting in the dark, surrounded by heaps of cash. Back in the present, Joe discharges Happy and heads for Ma's restaurant. There, Ma and nurse Miss Crutcher recall the time when Bill found out Carolyn was pregnant: After returning from the doctor's with Miss Crutcher, Carolyn breaks the news to Bill, who is ecstatic. Carolyn begins to calculate their future finances and is distraught when Bill confesses that he lost $1,400 gambling. They argue, and later, a guilt-ridden Bill takes a job as a waiter at a posh restaurant. One evening, Bill waits on Broadway producer George Craig and slips him a copy of his new play. Soon after, the play opens to rave reviews on Broadway. Carolyn is unable to attend the premiere, however, because she has gone into labor, two months before her due date. The baby dies and Carolyn, who can no longer bear children, is devastated. When Carolyn's depression persists, Bill decides to bring Timmy, whose mother has been hospitalized, to their Long Island home. Carolyn enjoys taking care of Timmy, and when Mrs. Wallace dies unexpectedly, the Blakeleys adopt him. In the present, Craig and his wife Helen discuss the Blakeleys' marital troubles, and Craig recalls the first time Bill worked with Janet: Just before an out-of-town opening, Bill receives a telegram from Carolyn telling him that she cannot make the premiere because Timmy has a toothache. Bill is disappointed, and later Janet, sensing his vulnerability, gives him a passionate kiss. In the present, Craig comments that Bill ended up casting Janet in all of his plays. Helen, who has had experience with homewrecking actresses, convinces Carolyn to grab a train to Philadelphia. Bill, meanwhile, is about to rendezvous with Janet when he reads Lawson's column. Panicked, he jumps on the next New York-bound train. Bill's train and Carolyn's train stop over at the same station, and the two spot each other. After reuniting, Bill swears that he has been faithful, while Carolyn cries with relief. The couple then head for the nearest hotel.