As Rebecca Hall's character, Beth, begins to settle into her serene lakeside dwelling — a poignant reminder of her life shared with her husband, Owen, portrayed by Evan Jonigkeit, before his abrupt and harrowing suicide — she finds herself haunted by an unsettling presence that seems to linger just outside her grief-stricken reality. The heavy silence of the house is occasionally broken by the creaking of the old wooden dock, once home to Owen's boat, serving as a haunting echo of his last moments alive.
As Beth grapples with the turbulent waters of her new existence, she is confronted by Becky (played by Samantha Buck), the mother of her student, Hunter. Frustrated by the C grade her son received — a grade that was assigned while Beth was still reeling from her husband’s death — Becky’s visit forces Beth to face a harsh truth regarding Owen’s demise; a gruesome and heart-wrenching narrative that leaves her with more questions than answers.
Beth's already rocky world experiences more upheaval when her best friend and confidante, Claire (illustrated by Sarah Goldberg), drops by during a grief counseling session. The weight of their shared sorrow looms heavily around them as they both strive to find solace amidst the emotional turmoil.
As Beth delves deeper into the enigma of Owen's life, she uncovers hidden floor plans for their home, indicating he was secretly constructing something prior to his tragic end. That night, she is suddenly startled by music echoing from below, a siren's call that urges her to explore further. A text on Owen's phone sends her rushing downstairs, where she is enveloped by an eerie sense of déjà vu.
The realities of life and death intertwine as cryptic messages begin to filter through the fabric of her understanding, sometimes sounding alarmingly like Owen himself. A low, gravelly whisper, reminiscent of her husband's voice, sends shivers coursing down her spine — or is it a figment of her already fragile mindset? Drawn to the window, she is struck by the sight of what appears to be Owen — breathtakingly naked on the beach, a vision that is both alluring and horrifying.
As the dream dissolves like early morning mist, Beth is left to ponder its significance — a manifestation of her grief or something more troubling? Her thirst for clarity drives her further down a rabbit hole of secrets, where she unearths a photo on Owen's phone that challenges everything she assumed about their shared life.
The day after Owen’s heartbreaking departure, Beth tries to find normalcy as she spends an evening with Claire and their circle of friends. But despite their best efforts to ignore the elephant in the room, the shadow of grief inevitably resurfaces. Claire reveals Owen’s final words in a chilling suicide note: > "You were right. There is nothing. Nothing is after you. You're safe now." This stark message triggers memories of Beth's own near-death experience, where she confronted the abyss of nothingness. She confesses to Claire the possibility that Owen's note might reflect an existential crisis eerily similar to her own feelings of isolation.
As the evening wears on, Beth sinks deeper into a numb detachment, ultimately finding herself alone by the tranquil waters of the lake house. It's as if she drifts into a waking dream, only to be shifted back to reality by what sounds like Owen’s ethereal voice calling out to her again. An exploration of the dock leads her to bloody footprints headed straight to her doorstep. Tentatively reaching out to what she cannot see, she is compelled to retreat inside, where a dream draws her back into a moment with Owen — an intimate encounter at their bedroom window — only for her to recoil in fear.
Once again awake, Beth seeks refuge in nature with a solo hike through the whispering woods. Her solitude is interrupted by Mel (portrayed by Vondie Curtis-Hall), a concerned neighbor walking his dog, who is aware of the depths of her sorrow and fears for her reckless wilderness sojourn. His invitation to lunch results in a chilling tale — a sighting of Owen with a woman who bore an eerie resemblance to Beth, a realization that sends Beth spiraling into disbelief. Digging further into Owen's belongings, she discovers unsought photographs showcasing an unfamiliar woman and others who strangely mirror her features. And then there is the ominous artifact: the Louvre Doll, its human form punctured by thirteen razor-sharp needles, serving as a chilling reminder that Owen's dark obsessions continue to stalk her even in death.
During a serendipitous visit to the bookstore, Beth finds herself in conversation with Madelyne (played by Stacy Martin), a figure strikingly similar to those captured in Owen's photographs. As they connect, Beth shares her tragic connection to Owen, revealing the agonizing story of his disappearance. Madelyne's expression betrays the weight of their intertwined stories with Owen, facilitating a growing tension in the air.
The haze of uncertainty begins to lift as Madelyne returns to Beth's home. Bearing witness to the profound emotional damage Owen's actions have wrought, Madelyne reluctantly unveils the truth about her relationship with Owen: although their interactions remained platonic, his sinister attempt to suffocate her led to her flight. This horrifying revelation sends Beth into a whirl of conflicting emotions, as she starts to question the very nature of the husband she loved.
Beth's spiral of grief intensifies when she stumbles upon a half-finished shed, which reveals a terrible sight that forever alters her understanding of Owen’s intentions. When the floorboards give way, she uncovers the remains of several women bearing striking resemblances to those haunting her dreams — a horrific discovery that solidifies her nightmare. In an attempt to confess this disturbing reality to Claire, her desperate voicemail is only met with silence, suggesting Claire is not ready to face the unspeakable horrors lurking at the core of Owen's twisted existence.
As Beth's grief morphs into alarming delusions, she finds ephemeral solace in the imagined presence of Owen, desperately urging a connection with what she believes is his spirit. However, the grim truth emerges — it isn't Owen's essence she seeks, but rather an insidious entity manipulating her mind from the shadows. This malevolent influence infects her consciousness, revealing visions of Owen's true nature — a malevolent being consumed by a destructive hunger for control.
The next morning, Claire's visit to the lake house reveals the extent of Beth's unraveling; she has taken Owen's boat and firearm, teetering on the brink of destruction under the demon's oppressive grip. Claire's pleas for help sharpens the air, leading Mel to respond to the impending crisis. As Claire supports Beth, glimpses of reality start piercing through her disorientation, yet her gaze remains fixated on the lake — as if staring into a chasm of terrors yet unseen. When asked what vision ensnares her mind, Beth responds with an unsettling calm, masking the darkness that steadfastly continues to haunt her.
