The story flashes back to a moment where Nath and Lydia are young children. Marilyn and James attend a Christmas party at Middlewood College. While there, Marilyn begins to talk to a professor in the chemistry department. She asks him to be his assistant, and the professor is shocked that Marilyn would consider a career while being a mother of two young children. James does not support Marilyn's choice to return to school. However, Marilyn holds on to the hope that the professor will call her back and offer her the job.
On April Fools Day, 1966, Marilyn receives word that her mother has passed away from a stroke. She tells Nath and Lydia, and both are slightly confused. They have never heard anything about their grandmother before. Alone, Marilyn drives to Virginia to clean out her childhood home. While rummaging through her mother's things, the only meaningful thing she finds is an annotated Betty Crocker cookbook. Frustrated at the smallness of her mother's life, Marilyn chooses to take only this item back to her home in Ohio.
While Marilyn is cleaning her mother's house, life at the Lee home begins to fall apart. James has "no idea how to cook eggs," and the kids are begging for Marilyn to return. One day, James takes Nath to the local pool. While there, Nath begins playing Marco Polo with some other children. James watches as Nath is bullied during the game—kids trick and tease him for being Chinese. James is visibly bothered after witnessing this exchange.
Upon Marilyn's return home, she vows to herself to make changes so that she does not live the same life as her mother. She calls the chemistry professor she met at the Christmas party in order to see if she has been chosen for the position. He laughs at her and explains that he did not think a mother of two young children would be capable of handling a career. He has chosen an undergraduate assistant instead. Frustrated, Marilyn drives to the hospital. While there, she is greeted by Janet Wolff, Jack's mother. Marilyn is shocked at the sight of a woman doctor, and she is motivated to change her life entirely.
For the next month, Marilyn prepares elaborate meals and embodies the ideal mother/wife. However, she is secretly planning to leave home and return to school. She does not tell anyone of her enrollment, and instead plans things discreetly. When she leaves without a trace, James, Nath, and Lydia are lost. The story flashes forward to describe Hannah's oblivion. She does not know anything about her mother's disappearance that summer. Instead, she retraces Lydia's steps on the last night she was alive, attempting to understand her sister's motivations.
The story flashes forward, and the police tell James and Marilyn that they have closed the criminal aspect of their investigation. They are under the impression that Lydia has committed suicide. Nath speaks to the authorities, but does not tell them the truth about his complicated family dynamics. Where would he begin? Hannah and Nath visit the lake, where Nath first admits that Lydia had once fallen in as a child.
Nath begins telling Hannah about the summer Marilyn disappeared. The reader learns about his father's heartache and about how Nath pushed Lydia into the lake and then saved her. Nath, overwhelmed with his family situation, begins studying outer space. Meanwhile, in Toledo, Marilyn discovers she is pregnant with Hannah. She returns home, to her family's delight. Unable to resume her studies, Marilyn begins to hope that she can live out her academic fantasies through Lydia.
Marilyn feels guilty about the fact that her domestic duties have thwarted her chances of pursuing a career. She attempts to be proactive, and her discussion with the chemistry professor at the holiday party gives her a glimmer of hope. However, James does not believe that it is appropriate for Marilyn to return to school. Instead, he wants to provide for the family with his stability as a tenured professor. In this way, James is defending his own masculinity and trying to prove himself as the patriarch. However, his insistence on these gendered roles ultimately causes Marilyn to have limited mobility and independence.
The news of Doris's death is a wake-up call for Marilyn. As she navigates her childhood home, she is overwhelmed with anger and aggression towards her dead mother. Although her home has some things that Marilyn could take back to her own house, she only chooses to take the Betty Crocker cookbook. This cookbook symbolizes Marilyn's deep-seated anger towards her mother. In addition, it serves as a reminder for Marilyn to consider pursuing her dreams and not merely living up to her mother's expectations.
Following Doris's death, Marilyn is particularly vulnerable and confused. When the chemistry professor denies her the assistantship, Marilyn feels stagnant and frustrated. Her accidental route to the hospital symbolizes the persistence of Marilyn's goals and how they have been central to her identity from an early age. However, upon her arrival, the sight of a woman doctor—Jack's mother—leaves Marilyn even more unsettled. This is the "final straw" that leads Marilyn to make significant changes in her life.
Throughout the novel, the realms of motherhood and career ambition are in tension. Although Jack's mother Dr. Wolff is pushing back against gender discrimination, she is viewed by the community as a selfish mother. Many members of the community see Jack's "delinquent" behavior as a direct result of his mother's "abandonment." In this way, the experiences of Dr. Wolff and Marilyn provide the reader with an insight into the difficulties of being an American woman in the 1970s.
The story about the lake indicates the significance of the body of water to the Lee family. This experience demonstrates the complex relationship between Lydia and Nath and the change in their sibling dynamic. Ng continuously interweaves the individual experiences of James and Marilyn into Hannah and Nath's narrative. In this way, Ng argues that there is no gap between the generations. Rather, Lydia, Nath, and Hannah all experience the residual effects of their parents' struggles and insecurities. This theme is central to the novel, as it ultimately becomes the reason why Lydia cannot continue living.