Jessie and Gerald Burlingame arrive at an isolated lake house in Fairhope, Alabama, for a romantic getaway. They come across a stray dog on the drive over, Jessie wants to help it but Gerald objects. While Gerald takes Viagra, Jessie cuts up a raw steak in the refrigerator and calls out for the dog to eat it. Gerald sees this and chastises her for it as the steak was expensive Kobe beef, but decides to allow her to leave the steak out. They enter the house and Gerald leaves the door open behind them. Inside, she changes into a new slip and Gerald restrains her with a set of handcuffs locked to the bedposts. He begins to enact a stranger rape fantasy; she half-heartedly plays along but soon becomes uncomfortable, telling him to stop and uncuff her. After a heated argument in which he accuses her of not even trying to rekindle their relationship, Gerald dies of a heart attack, falling on top of Jessie and leaving her trapped in the handcuffs.
A few hours pass. The dog enters through the open door of the house. Jessie tries to scare it away, but it bites a chunk out of Gerald's arm and eats it. Gerald stands up and begins talking; when Jessie notices his body remains on the floor, she realizes she is hallucinating. He taunts her about the truths of their strained marriage and his erectile dysfunction. He then informs her that she is beginning to suffer from dehydration and fatigue. Jessie also hallucinates a more self-assured version of herself, who explains things about her and Gerald that she never had the courage to acknowledge. The two hallucinations trigger her to remember the glass of water Gerald had left on the shelf above the bed, which she is able to reach; when she can't drink it, she rolls the shopping tag she'd torn from her slip into a drinking straw to reach the water.
Jessie falls asleep. While she's asleep, the dog appears to be startled by footsteps in the house and runs out of the house barking. Jessie wakes up in the dark, and sees a deformed obscured figure who reveals a bag of bones and trinkets. She refuses to believe the figure is real but Gerald says the figure is Death waiting to take her, pointing out that he must have been real because the dog ran out of the house. Gerald begins to call Jessie "Mouse", which triggers a memory of her father Tom, who affectionately referred to her as "Mouse." When she was 12, her family went on a vacation to see a solar eclipse from a boat. Jessie was scared of going on the water, so she chose to stay back to her mother's frustration and Tom agreed to watch her while the rest of her family went out on the boat. During the eclipse, Tom asked Jessie to sit on his lap, supposedly reminiscing about Jessie's early childhood, but began masturbating while Jessie was on his lap watching the eclipse. Tom gaslit Jessie afterward to cover up the abuse, pretending that he intended to tell her mother what happened but subtly implying that her mother would blame Jessie for it. Near the end of their conversation, he admitted that he did a "shameful thing", but could not look at her when saying that. Gerald then points out that Jessie never told her about this. Gerald and hallucination Jessie taunt that she never recovered from the assault, and that she married a man just like her father.
During her childhood memory, Jessie hallucinates the deformed man licking her foot. She them comes to and realizes it was the dog licking her foot and kicks it away. Gerald points out that it's only a matter of time before the dog stops eating his dead body and goes for hers. Gerald calls the deformed man "the man made of moonlight", and points out a bloody footprint on the floor, making Jessie realize the figure may have been real.
Jessie speaks to her child persona, who asks her to remember what happened afterwards. She then recalls eating dinner with her family and gripping a water glass so tight that it shatters and cuts her hand in the process after her mother asks how her time was with Tom while everyone else was on the boat. Her mother is shocked and seems to suspect something happened, but still does nothing, and Tom takes her aside to clean up her wound. In present day, Jessie hallucinates Tom and her younger self tending to the wound in the sink nearby the bed, and she realizes the only way to escape is to break the water glass, cut her wrist and use the blood as lubricant to free one of her hands from the cuff. She smashes the water glass, cuts her wrist, and peels back the skin, allowing her bloody hand to slip through the cuff. She first reaches for the phone only to see that the battery is dead.
Cast
Carla Gugino as Jessie Burlingame
Chiara Aurelia as "Mouse" (Young Jessie)
Bruce Greenwood as Gerald Burlingame, Jessie's husband
Carel Struycken as "Moonlight Man" / Raymond Andrew Joubert
Henry Thomas as Tom, Jessie's father
Kate Siegel as Sally, Jessie's mother
Adalyn Jones as Maddie, Jessie's sister
Bryce Harper as James, Jessie's brother
