Will Foust

Quick Facts

• Role: Primary antagonist; duplicitous husband of Sadie Foust
• First appearance: Early chapters as the handsome, “voice-of-reason” stay-at-home father proposing a move to Maine
• Family: Father to Otto Foust and Tate; legal guardian and uncle to Imogen
• Setting: From Chicago to a remote island in Maine
• Public image vs. reality: Affable teacher and devoted dad on the surface; calculating narcissist and murderer beneath

Who They Are

Will Foust is evil disguised as stability. Introduced as a sensitive, supportive partner eager for a “fresh start,” he orchestrates a controlled environment in Maine where he can manage appearances, isolate his family, and neutralize threats. Behind the charm is a cold strategist: the long-ago killer of Erin Sabine, the recent murderer of their neighbor Morgan Baines, and a man who weaponizes his wife’s dissociative identity disorder to do his dirty work.

Physical Description

Will’s beauty is not incidental—it’s tactical. His chiseled face and bright hazel eyes create instant trust; his youthful look lets him pass as younger and less threatening than he is. The cultivated “intellectual” aesthetic helps him blend into classrooms and neighborhood gatherings as the safe, thoughtful man everyone expects him to be.

Will wears his dark hair long, swept back into a low bun that’s growing in popularity these days, giving off an intellectual, hipster vibe that his students seem to like.

His looks function like camouflage: an attractive mask that lets a predator move through domestic spaces unnoticed.

Personality & Traits

Will’s character operates on a split screen. What he performs—gentleness, patience, vulnerability—directly conceals his core qualities: entitlement, calculation, and violence. The power of his facade isn’t just that people believe it; it’s that he uses it to make others doubt themselves.

• Facade

  • Supportive and “rational”: Presents as the family’s steady center—helping Otto with homework, soothing Sadie, and proposing Maine as therapeutic. These gestures keep suspicion at bay.
  • Charming and gregarious: Easily wins over neighbors and students, creating a protective social halo that makes accusations feel implausible.
  • Sensitive: Cries at movies and tough conversations, a practiced softness that obscures his capacity for cruelty.

• True Self

  • Manipulative and deceptive: A master of Deception and Manipulation, he gaslights Sadie and exploits her dissociative identity disorder to rewrite events—and recruit help.
  • Narcissistic and cruel: Other people exist to serve him; he shows no remorse for past or present killings.
  • Violent and murderous: Removes threats with ruthless efficiency, from Erin to Morgan, and plans to eliminate Sadie when she gets too close.
  • Greedy and opportunistic: Secretly siphons money from Imogen’s trust fund, reducing guardianship to a revenue stream.
  • Strategist of isolation: Rebrands flight as therapy—the move to Maine is less about healing and more about control.

Character Journey

Will does not “grow”; he is unmasked. The story begins with the believable picture of a flawed but loving partner seeking repair after Chicago’s crises. As Sadie’s suspicions sharpen and her alter Camille surfaces crucial memories, the narrative flips: the “fresh start” is revealed as a calculated retreat to a place where Will can manage witnesses, police scrutiny, and his wife’s reality. Each revelation strips away one layer of his persona until, in the final confrontation, he drops the act entirely—confessing past and present murders, attempting to silence Sadie for good, and finally dying when his victim refuses to remain one.

Key Relationships

• Sadie Foust: Their marriage is a case study in Gaslighting and Psychological Abuse. Will cheats, lies, and destabilizes Sadie’s trust in her own mind, then uses her diagnosis as both alibi and weapon. When she nears the truth, he shifts from discrediting her to planning her murder, proving his tenderness was always strategic.

• Camille: Infatuated with Will, Camille becomes the instrument he wields. He courts her loyalty, then coaxes her into eliminating threats like Morgan and a former student, Carrie Laemmer. Will treats Camille not as a person but as a function—proof of how completely he collapses the boundaries between intimacy and utility.

• Morgan Baines: Morgan is Erin Sabine’s sister and long-time skeptic of Will’s innocence. When she moves to the island and draws too close, Will uses Camille to murder her and then attempts to frame Sadie, showing his skill at weaving personal history into fresh crimes.

• Erin Sabine: Years before, Erin tried to end their engagement. Will killed her and staged an accident, sustaining a decades-long performance as a grieving fiancé. The elaborate cover-up foreshadows his later crimes and reveals how comfortable he is living inside a lie.

Defining Moments

Will’s power comes from planning—the appearance of normalcy is his favorite weapon. These turning points reveal how he engineers control.

• The move to Maine

  • What happens: Will sells the relocation as healing, taking the family to his late sister’s island home.
  • Why it matters: Isolation is leverage. Distance from Chicago reduces oversight and lets him manage Sadie’s narrative and the investigation’s periphery.

• The phone call to Officer Berg

  • What happens: Will retracts Sadie’s alibi on the night Morgan is killed, telling police she was out alone.
  • Why it matters: This is the hinge from covert to overt betrayal—proof he’s actively framing his wife and preparing her as the fall guy.

• The final confrontation

  • What happens: Cornered by Sadie’s discoveries, Will admits to killing Erin and Morgan and to manipulating Camille—then tries to murder Sadie.
  • Why it matters: The mask drops completely. His confession crystallizes the book’s central inversion: the “protector” is the predator.

• His death

  • What happens: Sadie kills Will in self-defense.
  • Why it matters: The narrative wrests control back from the abuser; survival becomes the counter-argument to his long campaign of domination.

Symbolism & Thematic Role

Will is the novel’s “wolf in sheep’s clothing”—a handsome, weeping husband who embodies the danger of trusting appearances. He personifies domestic evil that thrives in plain sight, demonstrating how charisma and intimacy can be tools of coercion. His exploitation of mental illness and family bonds deepens the book’s exploration of Trauma and Its Lasting Effects: his crimes don’t just end lives; they distort memory, shatter trust, and weaponize care.

Essential Quotes

A fresh start, he’d said, one of the many reasons we find ourselves transported to this home in Maine, which belonged to Will’s only sister, Alice, before she died.

This line captures Will’s favorite tactic: rebranding control as compassion. The “fresh start” reads as care, but it’s actually containment—geography as narrative management.

"I’ll tell you this, Sadie—you were never boring. I just never came up with a diagnosis for your condition."

Will’s faux-clinical tone reduces Sadie to a case study, revealing his detachment and contempt. He hides behind her diagnosis, using it to explain away inconsistencies and to justify manipulating her perception.

"You’re too smart for your own good, Sadie. If only you’d have let it be, this wouldn’t be happening. But I can’t have you go around telling people what I did. I’m sure you understand. And since you can’t keep your own mouth closed, it’s up to me to shut you up for good."

Here, the mask is off. He acknowledges motive (self-preservation), identifies the obstacle (Sadie’s insight), and declares his solution (violence). The chilling politeness—“I’m sure you understand”—underscores his belief that harm is reasonable if it serves him.

"You’d never do it, you stupid cunt."

The slur exposes his misogyny and the contempt beneath his curated gentleness. It’s also a tactical miscalculation: by underestimating Sadie, he catalyzes the resistance that ends his control.