Nathalie's considerably older husband George (Harvey Keitel) is a stern and prominent judge whose only weak spot is Nathalie herself. The two are happily married and enjoying their beach vacation. Their nearest neighbor, Lance (Craig Sheffer) is attractive, lively and has a childhood history with Nathalie. To Nathalie's dismay and chagrin, George ventures on an overnight fishing trip with Lance to clear the air between them.
Nathalie's initial reluctance is due to her fear of being left to her own devices, (of which the true reason is later learned). Anxious and longing for her husband, she receives an unexpected visit from an old lover named Kent (Billy Zane). Seizing her chance for company that night, she welcomes him inside and the two reminisce on old times. Kent reveals that his girlfriend recently left him because of his drinking problem; it is revealed that he has a medical condition which is worsened by alcohol. While Nathalie is in the bathroom, Kent takes it upon himself to grab a bottle of liquor from her husband George’s supply. The two whimsically frolic all night and the scene ends with them exhausted by the night’s activities. Come morning, Nathalie discovers Kent dead, apparently from alcohol poisoning.
Panicked and terrified, Nathalie quickly stores Kent’s naked lifeless body in a food cellar under the floorboard. When George returns from his fishing trip, she tries her best to conceal the night’s events and act normal. As the two talk, George notices the loose floorboard that is situated under the dining table. This is where the food cellar is located and Kent’s head is making the floorboard protrude outward. George stomps on the floorboard and corrects the problem. As Nathalie’s panic grows more desperate, George finds flowers and chocolate that Kent gave to Nathalie that night. Questioning her, Nathalie admits to Kent being present in the house the night of his fishing trip. When she reveals his location, George believing him to be still alive, taunts him. When Nathalie reveals that he is dead, George comes to understand the true desperateness of the situation. Taking his body to the nearby tool shed they debate at what course of action to take. The situation is further complicated because Kent’s clothes are missing and his neck was broken by George stomping on the cellar door. George being a prominent judge and Nathalie (as it is now revealed) having a history of early legal trouble for a pill addiction leaves them little option but to dispose of the body themselves. Although Nathalie still insists that the authorities should be notified and the situation explained, George insists that it is not possible.
The two decide to dispose of his body in the ocean with him being tied down with an old stove. As the two are carrying it to the house, Lance inadvertently shows up and foils their plan and the two are forced to rethink their original strategy. Nathalie and George return home and get into a heated argument. Nathalie expresses her disdain over George’s annoying ability to strangely store items in unconventional places, such as storing sausages in a cigar box. When George questions how Kent could have possibly died, Nathalie mentions his “weak heart” and the fact that he was drinking from George’s personal liquor supply. George reveals that “the blue liquor bottle” which Kent drank was in actuality not alcohol but a powerful liquid narcotic. Kent’s heart problems along with the powerful liquid drug led to his demise. As the two leave each other in frustration over not having disposed of the body, Nathalie goes out for a swim.
Coming back from her swim Nathalie notices Kent’s white linen suit resting on the porch of Lance’s house. Seeing her opportunity to do the right thing, she insists for the suit to which Lance happily agrees. Believing her troubles are over, Nathalie goes in search of George to reveal the good news to therefore dress Kent and explain their situation to the police. Nathalie spots George on the veranda. She sees blood embedded in the newly constructed concrete steps. It is revealed that George cut Kent’s body into pieces and mixed them in with the concrete steps. Horrified, Nathalie runs but is quickly captured by George. Having taken her back to the house and tied her up so she can’t escape George goes out to finish the rest of the work. Nathalie manages to free herself only to take refuge with Lance. She explains the situation and is relieved by Lance’s calm demeanor and support. The two are noticeably smitten by each other and it can be seen that Lance never really stopped loving Nathalie all those years. As Nathalie is in the house she notices a postcard intended for her. Lance says he meant to give it to her but forgot and insists he hasn’t read it. The postcard was in fact the very same one of which Kent spoke of foretelling his visit.
Nathalie quickly concludes that Lance knew Kent was coming all along and spiked George’s liquor supply in order to kill him. Horrified, she runs to George believing him to be an innocent victim in Lance’s murder plot. Lance insisting upon his innocence follows Nathalie outside to the beach. Shockingly, as Lance and Nathalie are confronted by George, the situation ends in a shootout in which George shoots Lance. Nathalie runs but is captured by George soon thereafter. George has been drinking heavily and is completely disoriented but manages to take Nathalie to the veranda and cement her legs shut in a metal crate. Finally revealing that he was in actuality behind the whole ordeal, George explains that he knew Kent was coming that night from Kent’s postcard he purposefully placed in Lance’s mailbox to frame Lance and keep Nathalie from knowing about Kent’s visit. He spiked the liquor before the trip, knowing Kent would drink and therefore killing him. As George is flailing about from being drunk he falls off the high rise veranda and is killed when the top of it falls down and pierces his body straight through. As a domino effect, Nathalie is thrown into the water but is unable to surface due to her cemented legs in the metal crate. Luckily, there is a local beach patrol boat nearby and Nathalie is rescued.
The scene ends with Nathalie in her own boat telling the beach patrolman her story from the very beginning. The patrolman being behind her, asks for a beverage and Nathalie tells him to check in the cooler under the seat. Unbeknownst to Nathalie, George had spiked a water bottle previously with Nathalie's medication and put it in the cooler.