On the morning of May 3, 1977, sixteen-year-old Lydia Lee does not show up at the breakfast table. Thinking that her daughter is still sleeping, Marilyn Lee ascends the stairs to enter her daughter's bedroom. There, she finds that Lydia's bed is untouched. Alarmed, Marilyn tells her two other children, Nath and Hannah, to hurry to school. She phones her husband, James, to alert him of Lydia's disappearance.
In his office at the local university, history professor James Lee is passively grading his student's papers. He is joined by his teaching assistant, Louise Chen. James is elated to have Louise as his teaching assistant, as she is the only other Asian person at Middlewood College during James's eighteen-year career. James is interrupted by Marilyn's phone call. He quickly rushes home to find police officers investigating the disappearance of his middle child, Lydia.
Upon hearing about Lydia's disappearance, Nath immediately believes that Jack Wolff is to blame. Lydia recently befriended Jack, the quintessential "bad boy" of Middlewood High School. Instead of promptly returning home after class, Lydia has spent the past few afternoons smoking cigarettes and driving around in Jack's Beetle. Nath grows infuriated at Jack, and he wishes to confront him and blame him for his sister's absence. However, Jack does not know anything about Lydia's whereabouts.
Hannah realizes that on the night of Lydia's disappearance, she saw a silhouette move across her family's yard. In retrospect, Hannah realizes that this was Lydia. Afraid that her family will chastise her for not chasing after her sister, Hannah keeps this detail a secret. The next morning, the police call after they notice a rowboat floating aimlessly on the town's lake. Shortly after James informs the authorities that Lydia does not know how to swim, the police pull Lydia's body fro the lake.
In order to explain Lydia's death, the story rewinds to slowly reveal the different factors at play. Ng begins by describing Marilyn's life. Marilyn was born in Virginia to Doris, a single mother who worked as a home economics teacher. Doris dreams of her daughter becoming a dutiful and responsible housewife. However, Marilyn dreams of becoming a doctor. After high school, she enrolls in Radcliffe College, where she encounters gender discrimination in her physics and chemistry classes. During her junior year, Marilyn enrolls in an American history class called "The Cowboy in American Culture." James Lee, a young, Chinese professor, is the instructor for the course.
Marilyn begins to develop a crush on Professor Lee. After Marilyn chooses to drop the course, the two begin dating. Marilyn is slightly embarrassed that she has started to date a Harvard man during her time at Radcliffe. Nonetheless, their relationship flourishes. The story then transitions to talking about James Lee's childhood. Though he was born in the United States, James has continually struggled with feeling unwanted by Americans. Throughout his education and during his career, he is incessantly taunted for his race and made to feel like an outsider. His relationship with Marilyn provides him with a comfort and sense of "home" that he has never before experienced.
Marilyn becomes pregnant with their first child, Nath. At the same time, James is denied a position as a professor at Harvard, and instead is offered one at Middlewood College in Ohio. The two leave Cambridge to begin their life together in Ohio, and Marilyn gives up her studies in order to prepare for motherhood. Marilyn's marriage is met with hostility by her mother, who disapproves of James's race. Doris's opinion ultimately causes Marilyn to cut her out of her life. Returning to the present, we see the Lees having a funeral for Lydia. Nath tries to beat up Jack, who shows up at the cemetery. James receives the autopsy, which confirms that Lydia died by asphyxia from drowning. Overwhelmed, James heads to Louise's apartment, and it is revealed that the two are having an affair.
Lydia's disappearance comes as a huge shock to the Lee family. Immediately following her absence, the family's equilibrium is deeply disturbed. Lydia, the fair-haired and favorite child, is no longer the object of her parents' doting affection. Each family member reacts differently to the news, which helps to reveal the individual identities of each character. Nath grows hyper-defensive and seeks to avenge her by attacking Jack, his sister's sole acquaintance at school. Hannah feels guilty that Lydia's appearance signifies that she will receive more attention from James and Marilyn.
The novel's transition to flashbacks reveals that Lydia's disappearance is closely connected to her family's complex dynamics. The reader first learns about Marilyn, and the tension between her and her mother, Doris. Although Marilyn aspires to be a doctor, her mother only hopes that her daughter can become a devoted housewife. Marilyn is deeply affected by the gender discrimination she experiences while attending Radcliffe College. Through her education, Marilyn discovers that it is incredibly difficult to pursue a career as an American woman in the 1950s.
The reader is then introduced to James Lee and the conditions of his upbringing. Although "born on American soil," James never felt integrated into American society. During his childhood in rural Iowa, James was the only Asian in his classroom. As a first-generation American, James understands the sacrifices made by his parents in order for him to have a brighter future. Interestingly, James becomes a professor of American history, specializing in the history of the cowboy. This career path demonstrates James's desire to assimilate into American culture despite the fact that he is continually rejected by American society.
James and Marilyn's relationship is incredibly unique, as the ban on interracial marriages was only reversed in 1967. Doris voices her disapproval of James on the basis of his race. This action deeply affects James. Although he feels "at home for the first time" with Marilyn, his relationship is not seen as "legitimate" in the eyes of Doris. Doris's disapproval, along with James's rejection from the Harvard history department, severely damage James's self-esteem.
James feels emasculated by those around him. Thus, Louisa Chen is the perfect opportunity to explore his racial identity through someone else. After he learns of Lydia's disturbing autopsy results, he immediately heads to Louisa's apartment for a rendezvous. In this way, Louisa becomes a form of escape for James. James feels power and authority through his extramarital affair.