Head Above Water

Nathalie and her husband George arrive at her family's remote island beach house in Maine to spend their vacation. Lance, who has known Nathalie since childhood, remains as caretaker. The quiet setting initially feels peaceful but hints at the tense events to come.

Kent, Nathalie's ex-boyfriend, arrives unannounced and claims his girlfriend left him due to his drinking. He makes a pass at Nathalie while drinking directly from a vodka bottle and eventually passes out on her marital bed. The incident foreshadows the brewing crisis.

Nathalie discovers Kent dead, apparently from alcohol poisoning, after waking up. In a panic, she stashes his naked body in the cellar beneath the dining area to avoid discovery. The decision sets off a dangerous cover-up that anchors the rest of the plot.

George returns from a fishing trip and notices the cellar door isn't fully closed, so he fixes it. He finds Kent's flowers and chocolate and Nathalie reluctantly confesses that Kent visited. The admission deepens the cover-up and raises stakes.

George, a prominent judge, and Nathalie decide they must dispose of Kent's body themselves due to the circumstances and Nathalie's past. They move the body to the tool shed and begin debating how to conceal the crime long enough to escape suspicion. The tension between duty, fear, and pride grows.

Lance arrives at the house, forcing Nathalie and George to rethink their disposal plans. They retreat back inside and realize Kent's clothes are missing and his neck shows signs of having been broken by the earlier struggle. The situation grows more perilous.

George discovers that Kent's bottle was not alcohol at all but methanol, a poisonous substance. This revelation turns the cover-up into a deadly complication with potential forensic consequences. The danger now is not just exposure but lethal poisoning.

Nathalie goes for a swim to clear her head, then returns to find Kent's white linen suit drying on the porch of Lance's house. She believes she may have found a way to fix things and looks for George to share the news. Instead, she discovers that George has started embedding Kent's dismembered body into the concrete steps.

Horrified, Nathalie runs but is captured by George and brought back to the house, where he ties and gags her. She eventually frees herself and goes to Lance to explain the situation. There, she finds Kent's missing postcard, and Lance claims it was forgotten.

Nathalie suspects Lance knew Kent was coming and switched the alcohol to kill him, but Lance denies involvement. He follows Nathalie outside to the beach, where the confrontation with George turns deadly when George shoots Lance. The fragile alliance between Nathalie and Lance begins to crack.

Nathalie escapes but is captured again; George, now heavily drinking, cements Nathalie's legs in a metal container. The violent struggle tightens around them as their options dwindle and the murder mystery spirals toward its end.

George loses his balance and impales himself after stumbling from the high veranda, while Nathalie sinks in the water because her cemented legs prevent surfacing. A beach patrol boat then passes by and rescues her, ending her immediate peril.

Back on her own boat, Nathalie tells the beach patrolman her story. He asks for a beverage, and she tells him to check the cooler under the seat. Unbeknownst to her, George had added some of Nathalie's medication to the patrolman's water bottle, setting up a chilling final twist.