Harrison Ford (Blade Runner)
Michelle Pfeiffer (Dark Shadows)
Katharine Towne (Evolution)
Miranda Otto (Lord of The Rings)
James Remar (Django Unchaiuned)
Diana Scarwid (Wonderfalls)
Jennifer Tung (Masked Rider)
Wendy Crewson (Air Force One)
Joe Morton (Terminator 2)
J.C. Brandy (Halloween)
Claire Spencer (Michelle Pfeiffer) is living in Vermont with her husband, renowned scientist Dr. Norman Spencer (Harrison Ford). One year previously, Claire had been involved in a serious car accident that leaves gaps in her memory. Combined with her daughter Caitlin’s (Katharine Towne) departure for college, this leaves Claire profoundly affected. The Spencers — who have moved into the former home of Norman’s father — live next door to the Feurs, who have just moved in and frequently engage in loud arguments. Overhearing Mary Feur (Miranda Otto) sobbing one day, Claire becomes concerned. When she sees Mary’s husband Warren (James Remar) seemingly dragging something that resembles a body bag in the middle of the night and putting it in the trunk of the car, she suspects that Mary has been murdered. Claire decides to investigate. After nobody answers the door, she walks around the side of the house and discovers a woman’s sandal with a dark stain on it. Claire begins spying on Warren with the help of her best friend Jody (Diana Scarwid). However, Claire soon witnesses strange occurrences when she is alone in the house and becomes convinced that Mary is dead and haunting her. Desperate for closure, and facing little sympathy from Norman, Claire invites Jody to join her for a séance in her bathroom, where she thinks she’ll be able to communicate with Mary’s ghost. Although the séance provides no results, after Jody leaves, Claire finds a message in the bathroom’s mirror that reads “You know”.
An anxious Claire goes to Norman’s office to inform him of the event, but he instead believes she’s trying to call for his attention because he’s been busy at work. As they argue while traveling through Norman’s campus, Claire encounters Warren and hysterically accuses him of having killed his wife. But Warren responds with confusion before Mary—very much alive—joins him. When Mary speaks with Claire later, she explains that she had left Warren and that he had been packing her belongings when Claire saw him.
The Spencers assume that the ordeal is over, but later a picture breaks in Norman’s study. Picking it up, Claire notices a newspaper clipping about a missing girl named Madison Elizabeth Frank (Amber Valletta). She learns that Madison attended the university where Norman was a lecturer. While visiting Madison’s mother she steals a braid of Madison’s hair. Reading from a book on the supernatural given to her by Jody, Claire uses the hair to perform a ritual that allows Madison to possess her. Norman comes home and Claire seduces him, but Claire morphs into Madison during the tryst, causing Norman to push her away. Claire’s memory returns, and she remembers that she had caught Norman and Madison together the night of her car accident. Outraged by Norman’s infidelity, Claire spends the night with Jody, who confirms to Claire her suspicion of Norman’s affair after having seen him and Madison together in a small cafe in the town of Adamant; unseen by Norman, Jody keeps this information to herself, until she confesses to Claire.
Norman eventually relents: he had a brief relationship with Madison, but realized that he loved Claire too much to leave her and ended the affair, causing the unstable Madison to threaten to kill Claire. He states Madison came to the house, and he found her dead of an overdose. Panicked and unsure of what else to do, he placed Madison’s body into her car, which he then pushed into the lake. Claire urges Norman to contact the authorities, and he agrees to do so. He speaks with the police on the phone, arranges for a police officer to come to the house and then leaves to take a shower. Suspicious of her husband, Claire redials the phone and discovers that he had not really called the police. Norman, who has been hiding and left the shower tap running, suddenly grabs her from behind and sedates her. He drags her to the bathtub, which is still running, and places her in the rising water with the idea that since she cannot move, will drown once the water rises high enough.
Norman then confesses to Claire that his previous story had been a lie; Madison was planning on going to the college’s dean about their affair, so he killed Madison and pushed her car and body into the lake. Norman then tells Claire he hopes her death will bring him closer to Caitlin, who looks so much like her. Norman leans over Claire’s paralyzed body to give her one final kiss. While doing so, he notices that she is wearing a pendant around her neck. When he picks up Claire’s head to adjust it, her face suddenly morphs into the corpse-like face of Madison. He is startled and jumps back, slipping on the wet floor and hitting his head on the sink; he is left bloodied and unconscious on the floor.
Claire, recovering from the sedative, looks over the edge of the bathtub to see that Norman has crawled away, while she was struggling to drain the water. Recovering from the sedative, she crawls out of the bathtub, eventually regaining enough strength to walk down the stairs. The phone has been disconnected, so she tries to drive somewhere that will have cell phone reception. Norman, only stunned at the bottom of the stairs, chases her and jumps into the back of the truck. A ghostlike figure appears in the road, which Claire swerves to avoid, and she drives off the bridge into the same lake into which Norman pushed Madison’s car. Underwater, Norman tries to drown her and grabs Claire’s leg as she escapes out the window, but Madison’s decaying body, disturbed by debris falling from the car, floats up, grabs Norman and forces him to release Claire’s leg, so she can swim to the surface. Norman drowns while staring into the dead face of the woman he killed. Madison’s body floats to the surface of the lake as the necklace sinks to the bottom.
The following winter, Claire places a single red rose on Madison’s grave. The camera pans out, and an image of Madison’s face appears in the snow.
While not as darkly disturbing as similar ghost stories, What Lies Beneath is as much a study of what underpins a relationship, and how quickly this can be betrayed and unbalanced, as a goosebump-inducing vision of what could be lurking at the bottom of the lake. The performances are faultless, the lakeside setting is used to perfection and the occasional use of gentle humour makes the story and characters even more likeable.