After her fiancé is killed in a car crash, Margot Weston goes to jump into the river, but she is stopped by Jim Howard, a drifter who used to be a good surgeon. Jim takes Margot to a maternity hospital, where she bears a son. Because she has no home, money or name to give the child, she gives the baby up for adoption to Jim's friends, Phillip and Jane Marshall, and agrees with Jim that the Marshalls and the boy must never know her identity. After Jim arranges for Margot to work at his friend Harriet Martin's modiste shop, he leaves on what he says will be a short boat trip. Five years later, Margot, now indispensible to Harriet, is about to leave for Paris on a fall buying trip when Jim, who has lived in the interim contentedly as a doctor on a cattle boat, returns. During a romantic dinner, Jim vows to remain. In Paris, the extremely flirtatious and persistent Count Giovanni Corini pursues and proposes to Margot, who good-naturedly tolerates his company. By chance she meets her son, five-year-old Roddy, who is traveling with Phil's sister, as Phil's wife has died. After learning that they are sailing back, she impulsively books a cabin on the same boat. Giovanni follows suit, and during the trip, Margot and Roddy develop a great affection for each other. At the docks, Margot meets Phil and his bride-to-be, Jessica Reid, who promises to visit Margot's shop to select bridal gowns. When Margot excitedly tells Jim, now a lab assistant, about Roddy, Jim persuades her not to see him again because of the agreement she made. However, Jessica brings Roddy to the shop, where Margot witnessses her yell at the boy and learns that she plans to put him in a military school so that she and Phil can travel. Although Jim argues against it, Margot schemes to make Phil see Jessica for what Margot thinks she is: superficial and selfish. After Margot and Phil have a pleasant outting together selecting a tricycle for Roddy, she brings Giovanni to Phil's house in Westchester, where Jessica now lives. While Giovanni flirts and dances with Jessica, Margot goes bicycle riding with Roddy. Phil, upon arriving, is overjoyed to see Margot. Jessica ignores Giovanni's professions of love and when she gets Margot alone, accuses her of trying to take Phil away. As Phil enters the room, Margot traps Jessica into revealing that she regards her conquest of him as a "business investment." That night, Jim, who credits Margot for inspiring him to become a full-fledged bacteriologist, is about to propose to her when Giovanni interrupts and joins their table. The next day, Phil, who has broken with Jessica, proposes to Margot, whom, he says, he has loved since he first saw her. Margot discusses the proposal with Jim and even though she loves Jim, decides to marry Phil to make sure that Roddy is loved and protected. She and Jim kiss passionately, and after they vow that no one else will ever know that Margot is Roddy's real mother, Margot comes to Phil's house to live.