This guide maps the interlocking cast at the heart of a small coastal community where a “fresh start” dissolves into suspicion, buried memory, and danger. Secrets inside a marriage collide with the echoes of an old crime, while competing narratives—some told by alters born of trauma—reframe what it means to witness, to remember, and to survive.
Main Characters
Sadie Foust
As the novel’s central voice, Sadie is a physician and mother whose move to a remote Maine island with her family draws her into the investigation of a neighbor’s murder and into the darker corners of her own mind. Intelligent yet anxious and deeply traumatized, she is an unreliable narrator shaped by a Dissociative Identity Disorder she does not initially recognize; her husband’s sustained gaslighting and psychological abuse exploits those vulnerabilities. Her relationships with Will Foust, her sons Otto and Tate Foust, and her niece Imogen are complicated by the presence of protective and volatile alters—Camille and Mouse/Delilah—who carry her worst memories and act where she cannot. As the truth behind Morgan Baines’s death surfaces, Sadie confronts the deception and manipulation at the core of her marriage, integrates her fragmented identities, and ultimately kills Will in self-defense to protect her children, claiming a hard-won sense of reality and freedom.
Will Foust
Beneath a disarming veneer of devoted father and supportive spouse, Will is the novel’s true antagonist—narcissistic, deceitful, and increasingly violent. He isolates and controls Sadie, weaponizing her disorder and carefully curating a façade of stability while concealing an older crime: the murder of his first fiancée, Erin Sabine. Discovering and seducing Sadie’s alter Camille, he turns her into an instrument, directing the killing of Morgan Baines when Morgan draws too near the truth about Erin. His unraveling is gradual but inexorable; as Sadie assembles the pattern of his past and present offenses, Will’s performance collapses into the raw threat of a man willing to kill again—until Sadie stops him.
Delilah / Mouse
Told in a chilling first-person account that opens the book, Delilah—also called Mouse—recounts years of captivity, a survival narrative that is ultimately revealed to be the childhood memories of Sadie’s trauma-holding alter. Resourceful and fiercely protective, especially of her fellow captive Gus, she endures abuse at the hands of “The Lady” (Charlotte/Shelby) and “The Man” (Eddie), the tormentors whose dungeon becomes the crucible for her resilience. When she sharpens a spoon into a weapon and escapes, the twist reframes the timeline: this is not a current abduction but the buried origin of Sadie’s dissociation. Mouse/Delilah embodies the cost of survival and the mechanisms the mind creates to endure, anchoring the novel’s exploration of trauma and its lasting effects.
Camille
Emerging as Sadie’s protector alter, Camille is impulsive, seductive, and aggressive—the embodiment of anger and desire that the cautious host personality represses. Will exploits her loyalty, initiating an affair and persuading her that violence is necessary to safeguard their bond, culminating in Morgan Baines’s murder. Camille’s perspective is distorted by manipulation but crucial to the plot: she exposes the ways Will infiltrates Sadie’s internal world even as she tries to defend it. Her presence complicates every relationship Sadie holds, blurring the line between protection and harm and revealing how abuse can co-opt even the parts of a person meant to keep them safe.
Supporting Characters
Imogen
Initially a gothic-tinged red herring, Imogen is Will’s sixteen-year-old niece who moves in after her mother Alice’s death by suicide. Blunt, grieving, and angry, she pushes against Sadie’s authority while hiding the unbearable guilt of having helped her mother die. Their volatile dynamic transforms at the climax, when Imogen intervenes to save Sadie’s life by striking Will—an act that recasts her as an unexpected ally and truth-teller.
Otto Foust
Quiet, artistic, and withdrawn, Otto is Sadie and Will’s fourteen-year-old son still reeling from severe bullying that once drove him to carry a knife to school. Sadie’s fear-lensed interpretations of his behavior—and of disturbing drawings she assumes are his—play into the book’s theme of unreliable perception and memory. In the end, Otto provides a small but pivotal observation that helps Sadie recognize Will’s manipulation, underscoring his role as a careful observer rather than a threat.
Morgan Baines
The titular “local woman,” Morgan becomes the present-day murder victim after she quietly reopens the cold case of her sister Erin’s death. Determined and discreet, she reconnects with Will under friendly pretenses while investigating him, inching dangerously close to confirming her suspicions. Her fate—engineered through Will’s control of Camille—links past and present and reveals how unfinished grief can provoke deadly confrontations.
Erin Sabine
A beautiful, carefree presence in Will’s past, Erin is his first fiancée and first victim, killed two decades earlier when she tried to end their engagement. Her death, long misread as an accident, is the anchor that holds the story’s present-day crime in place. Erin’s memory motivates Morgan’s investigation and exposes the pattern of violence that Will has refined over time.
Minor Characters
- Tate Foust: Sadie and Will’s seven-year-old son, whose innocent “statue game” echoes Mouse’s coping strategies and inadvertently surfaces clues.
- Gus: The frightened boy imprisoned alongside Delilah, serving as both her charge and the mirror of her ragged hope.
- “The Lady” (Shelby/Charlotte) & “The Man” (Eddie): The sadistic couple who abduct and abuse Delilah and Gus; the Lady is later revealed as Charlotte, Sadie’s abusive stepmother from a buried chapter of her childhood.
- Alice: Will’s sister and Imogen’s mother, debilitated by fibromyalgia and ultimately choosing assisted death; her loss precipitates the Fousts’ move to Maine.
- Officer Berg: The island investigator whose steady, methodical approach keeps pressure on the Foust household and heightens Sadie’s paranoia.
- Jeffrey Baines: Morgan’s husband, abroad during the murder and a deliberate red herring as suspicion swirls.
- Courtney Baines: Jeffrey’s volatile ex-wife whose public animosity toward Morgan makes her a plausible—but ultimately false—suspect.
Character Relationships & Dynamics
At the core of the novel is a marriage constructed as a trap: Will’s control depends on isolating Sadie, undermining her sense of reality, and commandeering her internal defenses. He transforms a family into cover, weaponizing Otto’s troubles and Imogen’s grief to keep the household chaotic and Sadie off balance. Meanwhile, Sadie’s maternal love for Otto and Tate, and her uneasy guardianship of Imogen, are the counterweights that pull her toward clarity and courage.
Sadie’s internal system functions like a clandestine family within the family. Camille, the protector, channels rage and decisiveness that Sadie cannot access, while Mouse/Delilah holds the pain of childhood abuse that Sadie’s conscious mind refuses to revisit. Will’s affair with Camille is a particularly toxic inversion of intimacy: he seduces the part of Sadie meant to keep her safe and turns it against both host and victim. This violation blurs the boundaries between agency and coercion, making the murder of Morgan Baines both a personal betrayal and a calculated erasure of witnesses to Will’s past.
The circle of victims—Erin Sabine in the past, Morgan Baines in the present—reveals the continuity of Will’s violence and the reach of its consequences. Morgan’s quest for truth creates an inadvertent alliance with Sadie, though they never meet as allies; each woman’s search destabilizes Will’s carefully maintained narrative. On the periphery, Officer Berg’s investigation applies steady external pressure, while Jeffrey and Courtney Baines serve as misdirections that reflect the community’s impulse to explain away danger without looking too closely at the man next door.
Factions emerge across these threads: the embattled Foust household; Sadie’s internal protectors; and the victims whose lives expose Will’s pattern. As these networks collide, fragile alliances form—most dramatically when Imogen turns from adversary to savior—culminating in a confrontation that forces truth into the open and breaks the cycle of control.
Character Themes
- Sadie Foust: The fragility of memory, the corrosive power of gaslighting, and the struggle to reclaim identity after trauma.
- Will Foust: Charisma as camouflage and the everyday face of predation; the banality and calculation of evil.
- Delilah/Mouse: Survival, dissociation, and the mind’s capacity to protect itself by dividing what cannot be borne.
- Camille: Uninhibited rage as both shield and weapon; how protectors can be co-opted by abusers.
- Imogen: Grief, guilt, and the danger of judging by appearances; the possibility of transformation from perceived threat to genuine ally.