The Other Emily

David Thorne, a thirty-seven-year-old bestselling novelist living in New York, is haunted by recurring nightmares and an unresolved loss. Every ten months he returns to his cottage in Corona del Mar, California, a shrine to Emily Carlino, the woman he loved, who vanished ten years earlier after her car broke down on a remote stretch of Highway 101. His creative talent is intertwined with a tendency toward obsession, and his time in California follows a painful cycle of hope and guilt.

On his second evening back, David sees a woman at a harborside restaurant who is identical to Emily: the same black hair, the same blue eyes striated in two shades. She introduces herself as Maddison Sutton, age twenty-five, the same age Emily was when she disappeared. Maddison claims to know David only from his book-jacket photos and denies any connection to Emily but agrees to dinner the following night.

David enlists Isaac Eisenstein, a private investigator and friend in New York, to run background checks. Isaac's facial-recognition software identifies photos of Maddison and Emily as the same person at the same approximate age, despite David's insistence they were taken a decade apart. Maddison's driver's license traces back to Patrick Michael Lynam Corley, a contractor who died of a confirmed heart attack seven years earlier. Isaac discovers that Maddison's claimed parents do not exist, her license is a forgery, and she is the sole real director of the small Corley Foundation. Patrick Corley has been sighted alive on three occasions since his death.

For six years, David has also been visiting Ronny Lee Jessup at Folsom State Prison, a convicted serial killer who abducted twenty-seven women over two decades, keeping some alive in an elaborate underground labyrinth beneath his house and mummifying others. Jessup confessed to all twenty-seven but refuses to reveal where he hid 14 victims whose remains were never recovered. David pays Jessup for access, ostensibly researching a book, but his true purpose is to determine whether Emily was among the killer's victims, since she disappeared along the same coast where Jessup operated.

David and Maddison grow closer. She is charming, witty, and unnervingly perceptive, speculating that Emily did not simply leave David but that he failed her at a critical moment. Her favorite color, flower, and time of day are all identical to Emily's. She claims her profession is "assassin," which David dismisses as a joke. After a Sunday afternoon together, she mentions an unpleasant evening task, "the assassination," and kisses him on the cheek. That night she enters David's cottage using a spare key hidden in the same spot Emily knew, comes to his bed, and calls him "Davey," as Emily did. During their growing intimacy, David discovers she has the same distinctive golden birthmark below her navel that Emily had.

David's investigation yields further unsettling discoveries. He finds calla lilies, Emily's favorite flower, on the unmarked gravestone he purchased for her. Cemetery footage shows Maddison delivering them, accompanied by the supposedly dead Patrick Corley. In a series of interviews, David learns that Estella Rosewater, a former business partner of Corley's, encountered him alive at a restaurant six years after his death. Gilbert Gurion, attorney for the murdered biotech entrepreneurs Ephraim and Renata Zabdi, reveals their company held key patents in bioprinting (3D printing technology used on living tissues) and recellularization (the process of growing new, functioning cells). Richard Mathers, a young criminal, recounts breaking into the Corley Foundation house on Rock Point Lane and finding a woman matching Emily's description in a trance, with a metallic disc embedded in the back of her skull. When he touched it, she jolted awake and screamed at him to leave.

Maddison visits Calista Carlino, Emily's blind mother, replicating Emily's voice and mannerisms so precisely that Calista becomes convinced her daughter has visited. In parting, Maddison tells Calista not to be afraid of what is to come. The following day, Calista dies of a cerebral aneurysm, and David realizes Maddison foresaw the death.

Maddison then vanishes, leaving a note asking for patience. When Jessup writes offering to reveal the location of the 14 hidden bodies, David flies to Folsom and confesses his deepest shame: He lied to Emily about a meeting and spent two nights with an actress, which is why Emily was driving alone the night she disappeared. Jessup reveals the bodies are in a secret chamber beneath the mummification room, accessible through a ceramic tile bearing a painted blue eye.

David descends into the hidden crypt and finds 14 mummified bodies, none of which is Emily. On a table of personal effects, he discovers the custom gold locket he designed for her, proof she fell into Jessup's hands. Her absence from the crypt gives him fragile hope. He also discovers that Stuart Ulrich, the property owner, has been secretly preparing the cellar to replicate Jessup's crimes. When Ulrich traps him in the labyrinth and draws a pistol, David kills him in self-defense.

David constructs a bomb and drives to the house on Rock Point Lane in a rainstorm. Inside, the house pulses with a deep throbbing from the basement, his watch stops, and rooms flicker between their current state and a decayed future version. A clone of Nanette Corley, Patrick's late wife who died of cancer 12 years earlier, appears and warns David he will die here. In this house, such clones serve as avatars: Bodies grown from DNA and operated remotely by beings from the future. Patrick Corley's avatar tells David the house is a "bridge between then and now, two points a hundred years apart," and that its occupants have traveled back in time to change the future.

In Maddison's bedroom, David learns the full truth. The woman's real name is Anna. She is a being from a century in the future whose consciousness is transmitted into a clone of Emily through a control pod, a device in the basement that bridges her mind and the avatar's body. Three such beings are on a mission to alter history by assassinating individuals whose work will lead to a catastrophic future of runaway technology and genetic manipulation. Anna explains that she fell in love with David after a memory scan extracted the complete memories from Emily's dying mind. Having lived through Emily's five years with David, Anna engineered their meeting. In her own time, Anna's body is grotesquely deformed, a product of genetic manipulation gone wrong. Operating Emily's clone gave her the first experience of beauty and love she had ever known.

David refuses to accept Anna as a substitute and demands the truth about Emily. Anna admits that the real Patrick Corley insisted they save Emily when she arrived at the house, stabbed and near death. They healed her and placed her in suspended animation in the basement, where she has remained for ten years. David demands her release. Anna rages at his rejection, and a violent confrontation ensues in which David shoots both the Emily and Corley avatars. When a third avatar appears with a pistol, he warns that his tote bag contains a bomb he can detonate instantly.

After a tense wait, Emily emerges from the basement, still twenty-five, wearing the same clothes from the night she vanished. David recognizes her by her authentic grace, distinct from the clone's imitation. He sends her to start the car, activates the bomb's sixty-second timer, and runs. As they speed away, the house erupts in a massive explosion, followed by additional concussions suggesting the collapse of the bridge between future and present.

Driving south through the fading storm, Emily tells David she remembers only being stabbed and then dreaming for what felt like a lifetime. When she asks what happened, he frames their story through the myth of Orpheus, who descended to the underworld to rescue his beloved Eurydice but lost her by looking back. This time, David tells her, he did not look back. The clouds begin to part, and moonlight finds the sea.