When snobbish cartoonist Larry Larkin loses the heart and warmth in his "Snips and Runty" comic strip, Dunreath Henry, Larry's private secretary and fiancée, hires another artist, Francis X. Dignan, to ghostwrite the strip. The sophisticated Dunreath fails to mention to Larry, however, that she was once married to Dignan, back when she was a small-town girl from Port Huron, Michigan named Ethel Jankowski. The down-on-his-luck, neurotic Dignan, who has gone from working for noted cartoonist Al Capp to painting turtles for boardwalk sideshows, has never fallen out of love with Dunreath. Though he initially turns down the job with Larry, Dignan later decides to take the well-paying position in order to finance his ongoing psychoanalysis. Upon arriving at Larry's Manhattan penthouse, Dignan is impressed to learn that Larry is about to adopt Norman Taylor, his recently orphaned cousin. It is soon apparent, however, that Larry's true incentive for adopting the young boy is publicity. Larry also tries to further his political aims by planning his European honeymoon with Dunreath around the travel schedule of a powerful politician, Senator Winston. Meanwhile, Dignan continues to self-destruct when the first time he is criticized by Larry, he attempts to quit, only to be turned into an errand boy. After Norman runs away from home, Dignan is sent to the police station to pick him up. Ordered to keep the boy away while Larry is doing a magazine interview, Dignan takes Norman to a carnival, and the two lost souls soon become fast friends. In a matter of days, Dignan has "Snips and Runty" back to its old form, but just as quickly, the usually pleasant Dunreath becomes nervous and irritable, though it is unclear whether the cause is her approaching wedding day or the continued presence of her ex-husband. Further, while Dunreath is unsure around Norman and Larry cannot relate to the child at all, Dignan quickly becomes the boy's surrogate father. Still unable to confront Larry directly, Dignan usurps his boss's authority by purchasing a large, mangy dog for Norman, rather than the living embodiment of "Runty" that the cartoonist had selected. Soon thereafter, Dignan is nearly fired by Dunreath after she sees his slanderous, yet accurate, impersonation of Larry during a rehearsal for the "Person-to-Person" television show. However, Gussie, Larry's maid, warns Dunreath that she still has some "zing" for her ex-husband, and with Larry's plane grounded in Washington by a rainstorm, a matchmaking Gussie arranges a private dinner for Dignan and Dunreath. The two become trapped in Larry's high-rise apartment when an electrical shortage grounds the building's elevators. After an amorous Dunreath becomes drunk on Gussie's "special martinis," Dignan finally confesses the reason behind the neurosis that broke up their marriage and hampers his career: he feels overwhelming guilt for getting his father fired after he beat up his father's boss's son as a young boy. The next morning, Larry returns home to find Dignan and his fiancée wearing matching Chinese honeymoon pajamas. With only hours left before the live "Person-to-Person" broadcast, Larry chooses to forgive Dunreath and fire Dignan, though he orders him to finish that Sunday's comic strip first. Dignan, however, takes the opportunity to destroy the comic strip by turning the wholesome "Snips" into a suicidal juvenile delinquent. Meanwhile, after being told by Larry that his late mother never loved him, Norman gets Dignan's help in recovering a prized toy elephant that she had given him. Filled with the antacid medication to help calm his queasy stomach, Dignan interrupts the live television broadcast and finally confronts Larry and confesses his undying love for Dunreath. In turn, Dunreath finally realizes she is still "plain old Ethel Jankowski," and breaks her engagement to Larry. Along with Norman and Gussie, she then joins Dignan to begin a new life together.