Charlotte explains that she had a consensual affair with a man who was poor, unhappy, and about to leave the country. She insists she was not taken advantage of and that the man does not know about the baby. Under Delia’s intense questioning, Charlotte makes a destructive revelation: The child’s father is Clement Spender, Delia’s former love. The affair occurred after Clem returned to New York and discovered Delia had married Jim Ralston; he had learned the news just as he was delivering Delia’s wedding gift, the clock on her mantelpiece.

Charlotte explains she came to Delia because Clem had loved her. She is desperate, as she cannot marry Joe Ralston if it means giving up her baby to an institution. Delia, though deeply affected by the news, feels a strange connection to Charlotte’s confession. Overwhelmed and realizing the urgency of the situation, she tells Charlotte to wait. Donning a bonnet and veil, Delia leaves the house, needing to walk and think about how to handle the crisis.

Distraught, Delia leaves her house to think and walks to the day nursery that Charlotte runs. There, she identifies Charlotte’s child, a frail little girl called Teena, by recognizing the late Clem’s features in her. Deeply moved, Delia holds the girl, gives her a gold chain, and whispers goodbye, calling her “Clementina” before leaving.

Returning home, Delia finds Charlotte still waiting and announces her decision: Delia will keep the child to save her from an uncertain fate. The shock causes Charlotte to have a hemorrhage. Delia reassures her cousin that she has not told her husband, only that she has just been to see the baby. She asks for Charlotte’s trust and time to arrange things. The two cousins sit together for hours until Charlotte departs, filled with a new sense of hope for the future.

Delia’s husband, Jim, brings his cousin and Charlotte’s fiancé, Joe Ralston, home for dinner. Joe is distraught over Charlotte’s refusal to give up her personal work at the day nursery. He asks Delia to persuade Charlotte to cease her involvement, fearing the risk of disease. Delia realizes she faces a dilemma: She cannot allow Charlotte to dishonorably marry Joe without revealing her past, but knows the truth would end the engagement. To protect Charlotte’s secret and save the child, Delia decides to sacrifice her cousin’s marriage.

She tells Joe that Charlotte coughed blood that very day. This disclosure, together with the prospect of hereditary illness and a dying wife, convinces Joe to call off the engagement. Later that night, Delia uses her husband’s praise for her “wisdom” and his sympathy for Charlotte to secure his promise of financial support for the neediest child in the nursery without revealing her as Charlotte’s daughter.

Delia visits Charlotte, who is feverish and distressed in bed. Fearing the worst, Charlotte believes Delia has come to say that Jim will not permit them to take in her child, Tina. Delia clarifies the situation, explaining that Charlotte cannot marry Joe Ralston and also keep her daughter. Instead, Delia presents an alternative: Charlotte must break the engagement, and in return, Delia will adopt Tina, allowing Charlotte to live with and care for her own child.

Delia explains to Charlotte how she framed Charlotte’s health as the reason for Joe to break his engagement with her. She warns Charlotte that the entire arrangement depends on her holding to that story and ending the relationship for good. After a moment of tearful consideration, a resigned Charlotte agrees to the plan. She gives Delia her diamond engagement ring from Joe, confirming her decision to sacrifice the marriage for her daughter.

Charlotte fulfills her expected public reputation as an old maid, owing to the illness that she experienced in her youth and eventually led to the end of her engagement. It is publicly believed that Dr. Lanskell recommended for Charlotte to care for a foundling, so that she could channel her maternal instincts in a child. Delia arranged for Charlotte to live on a farm with the baby, Tina. Years later, after Jim was killed by a fall from his horse, Charlotte and Tina moved in with Delia’s family. Tina, now a vivid young woman, calls Delia “Mamma” and Charlotte “Aunt Chatty.”

During a dinner with a visitor, Tina affectionately calls Charlotte “dreadfully old-maidish,” which deeply upsets her. Later, Delia scolds Tina for being disrespectful. Charlotte overhears and confronts Delia, indicating that her old-maid persona is a necessary, painful sacrifice. She insists that Tina must always see her as a ridiculous old maid for her to “feel safe with her” (132). Delia pities the tragic spectacle of this unacknowledged bond. Charlotte’s resolutely states that she need not be pitied: “She’s mine.”

After Delia’s own children marry and move out, the unwed Tina becomes the household’s central focus. Both Delia and Charlotte silently worry about Tina’s marriage prospects given her secret parentage.

Following the departure of Delia’s daughter, Charlotte asks to move into the now-vacant bedroom next to Tina’s. Delia is privately irritated, as she had planned to convert the room into a sitting area for Tina, a space that would have preserved their intimate evening talks. Delia feels resentful that Charlotte’s silent determination always overrules her on matters concerning Tina, and she suspects Charlotte may be jealous of her influence.

After reluctantly agreeing to the room change, Delia feels cut off. Later that night, however, Tina secretly comes to Delia’s room to say goodnight, affectionately calling her “Mamma.” The visit reassures Delia that her bond with Tina remains unbroken despite Charlotte’s proximity.

While Tina is out, Charlotte confronts Delia, insisting they discuss Tina’s future. Charlotte reveals that Lanning Halsey, who has been courting Tina, has decided he cannot afford to marry her but intends to continue their relationship. Delia is concerned, but Charlotte explains the deeper problem: She believes the ambiguity of Tina’s parentage will cause every respectable suitor to find a similar excuse not to marry her.

Fearing Tina might be tempted into an affair, Charlotte announces a radical solution. To save Tina from a future as either a spinster or a mistress, Charlotte must take Tina away from Delia’s home and New York society entirely. They will move somewhere unknown to live a simpler life where Tina can find a husband. Delia is horrified by the plan, fearing it will only drive Tina to rebellion, but she feels powerless as Charlotte ends the tense conversation, reasserting her maternal authority.

After her talk with Charlotte, Delia reflects on her passionless life as a Ralston, a path she chose after the day Charlotte made her terrible avowal. Feeling a renewed desire to live for herself, she is disturbed by the sound of Charlotte going downstairs late at night.

Delia watches from her window and is stunned to see Tina walking home from the ball alone with Lanning Halsey, sauntering like lovers, despite the fact that someone else was supposed to have taken her home. The sight gives Delia a powerful revelation, as she suddenly understands how Charlotte must have secretly met with Clement Spender years ago. She realizes Charlotte’s own past fueled her suspicion, prompting her to go downstairs to intercept her daughter. Delia imagines the polite but firm scene Charlotte will enact to dismiss Lanning without scandal. The sounds from below confirm her prediction; Lanning leaves, and Charlotte and Tina return to their rooms, leaving Delia with this new, deep insight.

Feeling that decisive action is harder at 45 than it was at 25, Delia visits the respected family physician, Dr. Lanskell, for advice. He encourages her to ignore society’s judgment and reveals a stunning secret: Delia’s late husband, Jim, knew Tina was Charlotte’s child all along and had greatly admired Delia’s actions.

Bolstered by this revelation, Delia confronts Charlotte, who remains determined to leave with Tina, rather than allow her to marry under false pretenses. Delia then announces her plan to legally adopt Tina, giving her the Ralston name and the Lovell family inheritance. Charlotte insists they must leave instead, arguing that departing is what Jim would have approved and that pride in her child is all she has left.

The confrontation escalates until Charlotte, overwhelmed by a painful maternal renunciation, relents and begins sobbing. Delia comforts her, and Charlotte silently accepts the plan by taking Delia’s hand and kissing it.

On the eve of Tina’s wedding to Lanning Halsey, Delia intends to give her adopted daughter the traditional pre-bridal counsel. Charlotte confronts her, fiercely claiming that right as Tina’s birth mother. In a painful argument, Charlotte accuses Delia of having stolen her child’s affection out of a lingering love for Tina’s father, Clement Spender, and of having acted from that motive all along rather than pure generosity.

Wounded but compassionate, Delia relents and allows Charlotte to go to Tina. A short time later, however, Charlotte returns: She had stood in the passage unable to think of what to say without revealing their secret, and concedes that Delia is Tina’s true mother in every meaningful way. After sharing a tender moment with a blissful Tina, Delia makes a final request: that as she leaves for her new life, Tina give her very last goodbye kiss to her Aunt Charlotte.