Based on Edward Knoblock's play The Lullaby, Helen Hayes won a well-deserved Oscar playing the self-sacrificing mother of an illegitimate son.
In Paris Alice tells Dr. Dulac (Jean Hersholt) she is going to leave her busy physician husband. So he tells her the story of Madelon. Larry Maynard and young Madelon (Helen Hayes) leave her parents' house by the bedroom window for Paris. A critic dislikes his painting, and Larry gets a cable to return to America. Madelon believes "you have to pay for everything" and cries.
Just having given birth, Madelon wishes the baby were dead until he is brought to her. She thanks Carlo (Lewis Stone) for money and gives him a painting. She is planning to marry the farmer Hubert even though she does not love him; but when he refuses to take the child, that falls apart. Her father disowns her too. Rosie and Victor Lebeau take care of her child while she gets money from Carlo. Madelon visits her son Larry on his birthday, and a photo is taken. When Rosie and Victor need 10,000 francs, Madelon gives them a ring she got from Carlo. While Madelon and Carlo are dining out, Rosie tells them the ring is stolen. Carlo is arrested and shoots himself. Madelon is found guilty of being his accomplice and is sentenced to ten years. Rosie visits her in prison and will keep the boy without telling him his mother is there.
Madelon gets out of prison in 1919. After Victor was killed, Rosie had to put the boy into a charity school. Madelon goes there, but they will not give him to her unless she can support him. Dr. Dulac tells Madelon about young Larry and introduces him to her. He wonders why his mother never writes and asks where she is. Madelon tells him she is dead. Larry likes Madelon and gives her a kiss. When Madelon can't find a job, she finds herself being picked up by men and taking their money to enable Larry to study medicine and become a doctor. In this way Dr. Dulac even has the money young Dr. Claudet (Robert Young) needs for a serum. As an aging lady Madelon is about to sign herself into an institution she can never leave, but first she visits Dr. Claudet's home. She is taken for a thief, and then Larry examines her, asking about her son. He wants to help her find her son, but she leaves. Dr. Dulac tells Alice her husband Larry is helping Madelon even though he doesn't know who she is. Amazed by this story, Alice promises Larry she will reform.
What society considers are Madelon's sins are shown to be selfless sacrificing so that her son could have a good life. Spending ten years in prison for what she did not do, she certainly paid for more than her own sins, and her example became an inspiration to her daughter-in-law.