Beneath is a thriller-horror film co-produced in a first time partnership between Paramount Classics (a Viacom subsidiary) and MTV Films (although both co-purchased the rights to Hustle & Flow in 2005). The film is directed by the newcomer Dagen Merrill, who co-wrote the script with Kevin Burke, and the list of producers include Sean Covel and Chris Wyatt (Napoleon Dynamite, Think Thank), as well as Troy Craig Poon. In Paramount Classics's first horror movie, which marks the company's expansion from acquisitions into the production arena, the cast includes Nora Zehetner (Brick, May, R.S.V.P., Everwood) and Matthew Settle (U-571, Band of Brothers). Shooting started 2005 in Vancouver, the film was released on DVD August 7th, 2007.
The film starts with Vanessa and Christy visiting their parents grave and Vanessa gifting a chain to Christy for her 14th birthday. As they leave the graveyard, Christy insists on driving and ends up crashing the car. While the impact of the crash throws Christy away to safety, Vanessa gets stuck in the car that explodes and she survives disfigured and totally burnt.
Christy is sent to Pine Bluff Psychiatric Care Center for treatment while her sister is treated by her husband Dr. John Locke (Matthew Settle), at home with the assistance of the nurse Claire Wells (Eliza Norbury), and his rather stern mother, Mrs Locke (Gabrielle Rose). When Vanessa has a heart attack and dies, Christy has a breakdown at the funeral service screaming that her sister is alive in the coffin.
She then she moves to California for her pre-med, but remains haunted by nightmares and weird visions. She is sacked from her job due to her unstable condition and when the caretaker of the family Joseph (Don S Davis), dies six years later, Christy returns to Edgemont for the funeral and gets a cold reception from John and his mother. However, her niece Amy (Jessica Amlee), who is afraid of "dark things" behind the walls of the house asks her to stay in the town for a couple of days and Christy's friend Debbie (Nicola Anderson), welcomes and lodges her in her house.
Christy has mysterious blackouts with strange visions, the most prominent of them being a scarred, burnt woman clawing at a lid. She decides to investigate the death of her sister that she believes had been buried alive, disclosing a dark secret, while the locals believe she has borderline personality disorder. She befriends a cop, Jeff (Warren Christie), and starts uncovering the house's dark tunnels and passageways looking for the "dark things" that lie hidden there. She discovers that her sister was treated in the basement of the house and the room had tunnels connecting it to the rest of the house.
John and Mrs Locke resent Christy's influence on Amy and her presence in the house and ask her to leave. Christy leaves in search of Claire Wells, the nurse who treated her sister. She visits Claire's father who tells her that the Locke's are evil and ruined Claire's life and Claire broke relations with her family and left the state after Vanessa died. Meanwhile Mrs Locke dies (something Christy sees before the actual incident) and Christy returns to the house.
Amy again tells Christy about the monster who comes into her room through the wardrobe when she is sleeping and touches her cheek. While in Amy's bedroom, Christy hears noises from the wardrobe and follows the tunnels through to the basement. She has another blackout and when she wakes, she discovers John next to her with scratches on his cheek. He insists she leave the house and Edgemont immediately if she wants him not to press charges. She leaves in the dark and goes straight to the boathouse on the property. There she discovers a love letter hidden in a chest written by John to Claire. The letter reveals the affair between John and Claire and John is suggesting that Vanessa's death would be best for everyone. Christy is now convinced that John and Claire plotted to kill Vanessa and gave her medication which would induce a heart attack.
Christy takes her findings to Jeff and together they meet the medical staff at the hospital who were connected to her sister's treatment. The doctor tells her that he had very little involvement with Vanessa's treatment as that was entirely presided over by John and Claire. He also mentions that it would be impossible to prove whether she was murdered or not as her body was not embalmed and would have decomposed completely by now making an autopsy impossible. Christy points out that an autopsy is not required as the underside of Vanessa's coffin lid would show scratch marks and contain her broken fingernails proving she was alive at the time of her burial.
No one believes Christy and Jeff also advises her to immediately leave town unless she wants to be arrested. Angered and alone, Christy goes to the graveyard and pulls out her sister's coffin. She is shocked to see that there are neither any fingernails nor any scratchings. She goes back to the house and apologises to John and is about to leave when she gets a phone call from Jeff. She realises that the woman buried was not her sister at all but Claire Wells. John attacks Christy but she shoots him with his gun.
She then searches the house again and discovers an underground cellar wherein lies a badly disfigured, burnt monster of a woman - Vanessa. Vanessa does not recognise Christy and attacks her. They both fall into the water and Vanessa sees the chain around Christy's neck. They sit on the corner of the water and she realises its her sister. She cannot speak but Christy assures her and promises to take care of her. Christy realises that the Locke's and Claire kept Vanessa confined in the cellar and the visions she had were of Vanessa scratching the cellar trap. Vanessa would travel through the tunnels of the house and discovered the affair after which she killed Claire. She also killed Mrs Locke and would visit her daughter through the wardrobe.
There is a touching moment between Vanessa and Christy when suddenly a knife is driven through Vanessa's heart and she falls into the water and dies. She is stabbed by her own daughter Amy who says "I killed the monster". Amy does not know its her own mother.
In the last scene, we see Christy scattering Vanessa's ashes into the lake. Amy takes a picture and there is a vision of Vanessa prior to her accident, with an old fashioned wheel chair, staring at her killer. Its left upto the viewer to conjecture that Vanessa is either going to haunt her child and sister for her death just when she had finally found some respite or thanking her for releasing her from her bondage.