Emma in the Night

Three years after teenage sisters Cass and Emma Tanner vanished from their wealthy Connecticut home, 18-year-old Cass appears alone on her mother's doorstep. Emma's car had been found at a local beach with her purse and shoes inside, leading authorities to suspect she drowned. Cass's belongings were never found, and the case went cold. Now Cass returns with a desperate plea: Emma is still alive, held captive on an island off the coast of Maine, and the FBI must find her.

The novel alternates between Cass's first-person account and the third-person perspective of Dr. Abigail Winter, a forensic psychologist with the FBI. Abby has been haunted by the Tanner case since the original investigation, during which she developed an unproven theory that the girls' mother, Judy Martin, has narcissistic personality disorder, a condition in which profound insecurity produces a grandiose alter ego sustained through others' admiration and submission. Abby's theory was dismissed by her mentor, Special Agent Leo Strauss, partly because physical evidence turned up nothing and partly because Abby's own history with a narcissistic mother made colleagues question her objectivity. When Leo calls with news of Cass's return, Abby races to the Martin house.

Cass's story unfolds across days of interviews. She claims that on the night they disappeared, she hid in Emma's car and followed her to the beach, where Emma met a couple named Bill and Lucy Pratt. Emma was secretly pregnant, Cass explains, and had arranged through a trusted adult to stay with the Pratts on a remote Maine island. Cass says she chose to stay and protect her sister. Life there was initially pleasant, with Lucy homeschooling them, but after Emma gave birth to a daughter, Lucy claimed the baby as her own, refusing to let Emma hold or feed the child. When Emma fought back, Bill struck her. Cass describes a failed escape attempt in a rowboat and a horrifying dock confrontation in which Bill dangled the baby over freezing water and kicked Emma's bleeding hands away to stop her from climbing out of the ocean. She says she eventually escaped by manipulating the boatman, Rick, over many months, exploiting his guilt about a gang rape he witnessed on an Alaskan fishing boat.

Throughout the interviews, Cass insists her mother remain in the room. Judy repeatedly interrupts, questioning Cass's sanity. Abby notes oddities in Cass's behavior: compulsive counting of minutes and seconds, sophisticated psychological vocabulary, flat delivery of traumatic stories, and an intense gaze directed at Abby during key moments. Abby begins to wonder whether Cass's demeanor reflects genuine trauma or calculated manipulation.

As investigators search for the island, Cass reveals hidden family history. The household included Judy; her second husband, Jonathan Martin; and Jonathan's son, Hunter Martin, who had long been obsessed with Emma. Cass tells Abby that Judy once cut off Emma's hair with scissors in the middle of the night as punishment after Cass asked to live with their father, Owen Tanner. She directs Abby toward Lisa Jennings, a former school counselor, claiming Lisa helped Emma find the Pratts. When Abby and Leo visit Lisa, she inadvertently reveals knowledge of the hair-cutting she could only have gotten from Jonathan. Pressed further, Lisa confesses to an affair with Jonathan that was ongoing when the girls disappeared. Abby realizes Cass sent them to Lisa not for information about Emma, but to ensure Judy learned about the affair, destroying her trust in her husband.

The boatman is identified as Richard Foley through his connection to the Alaska incident. His rented boat, the Lucky Lady, is found drifting near Rockland, Maine, out of gas two days before Cass returned home, a discrepancy from her timeline. Investigators locate the island of Freya, owned by a corporation registered to Carl Peterson, Bill Pratt's real name. A tactical team raids the island and finds it exactly as Cass described, but the Pratts and Emma are gone. The only item recovered is Emma's angel necklace, its chain broken, taped to the underside of a bed frame. The necklace had been a source of tension between the sisters: Cass picked it out, but Judy bought it and gave it to Emma.

Alone that night, Abby studies the house layout and discovers that Cass's claim of seeing Emma through a window across the courtyard is impossible: The room described as Emma's has windows facing only the ocean. This flaw, combined with timeline discrepancies and Cass's selective lapses in her otherwise compulsive time-counting, leads Abby to conclude that Emma was never on the island. She tells Leo, and together they devise a plan.

They return to the Martin house and tell the family that Emma has been found alive at a cabin in northern Maine. The fabrication is designed to break Judy: If Emma is alive, then the secret Judy carries about her husband burying a body cannot be true. Judy confronts Jonathan violently. That night, she breaks down, and Cass comforts her while whispering the reassurances Emma always used.

The lie works. Jonathan returns, and he and Judy drive to a river gorge in the middle of the night. Abby, Leo, and Cass follow. Jonathan digs into the soft ground while Judy sobs. He unearths bones. Cass breaks free and runs to the grave, where she sees her sister's skeletal hand emerging from the earth.

The true story emerges in interlocking sections from both narrators. A week before the disappearance, Cass and Emma saw their mother having sex with Hunter through the kitchen window. Shattered, Emma confronted Judy, claiming Hunter had raped her and gotten her pregnant. This accusation was a lie Cass devised to test whether their mother would protect Emma. The confrontation turned physical on the upstairs balcony; Judy pushed Emma, who fell over the railing to the floor below. Jonathan arrived, found the body, and together with Judy buried Emma near the gorge and staged her car at the beach to simulate a drowning. Cass witnessed the fall from her doorway, grabbed the broken necklace, climbed out her window, and fled.

Cass walked to the train station, rode to New York, and found a hotline for runaway teenagers. The man who answered was Bill. He and Lucy took Cass to their island. Everything she described about island life was true, but it happened to her, not Emma. The baby was hers, fathered by Hunter the previous summer when Cass was 15. The Pratts took the baby just as she described, and all the captivity was her own experience. On the night she escaped, she drugged Bill, collected her daughter, and went to the dock. When Rick refused to let her leave with the child, she struck him with a metal gas container, knocked him overboard, and ran the boat over him, killing him. She traveled to the home of Witt Tanner, her older half-brother, left her daughter with Witt and his wife, and returned to her mother's house to execute her plan.

Jonathan takes a plea deal for obstruction of justice. The jury convicts Judy of obstruction and related charges but deadlocks on the manslaughter charge, unable to determine whether Judy or Jonathan caused Emma's death. Abby shields Cass from prosecution by testifying that her lies resulted from short-term dissociative disorder, a fabricated diagnosis. Leo buries a witness report from a woman who saw Cass traveling with a little girl.

In the final chapter, Cass moves in with Witt and reunites with her daughter. She acknowledges the darkness inside her and fears the cycle of narcissism may have passed to her child. Witt reveals he has been teaching the little girl to call Cass "Mommy" and has given her a new name: Emma. Cass holds her daughter and feels, for the first time, that her heart is full.