In 1931, the patients at the Vannacutt Psychiatric Institute for the Criminally Insane revolt against the staff headed by the sadistic Dr. Richard B. Vannacutt. The patients start a fire which engulfs the building, killing all of the inmates and all but five of Vannacutt’s staff.
In 1999, Evelyn Stockard-Price is in a disintegrating marriage with Steven Price, an amusement park mogul. At Evelyn's insistence, Price stages her birthday party at the long-abandoned hospital. The building's owner, Watson Pritchett, is convinced it is evil, having lived there as a child when it was converted to a private residence. Five guests arrive for the party: film producer Jennifer Jenzen; baseball player Eddie Baker; former television personality Melissa Marr; Donald Blackburn, a physician; and Pritchett himself. The guests are not the ones Price invited and neither of the Prices know who they are. Despite this, Price continues the party's advertised theme, offering $1 million to each guest who remains in the house until morning; those who flee forfeit their $1 million to the others.
The building's security system is mysteriously tripped, locking everyone inside – a stunt which Price blames on Evelyn. Jennifer, Eddie and Pritchett search the basement for the control panel. While exploring the labyrinthine basement, Jennifer confesses to Eddie that her real name is Sara Wolfe, the recently fired assistant to the real Jennifer. She impersonated Jennifer hoping to win the prize money. Shortly after, Sara is nearly drowned in a tank of blood by a ghost impersonating Eddie, but the real Eddie arrives in time to save her. Melissa subsequently disappears, leaving behind a massive trail of blood. Price visits his assistant Schechter, who is supposed to be managing the party stunts, but finds him horribly mutilated. On the surveillance monitor he sees the ghost of Dr. Vannacutt walking around with a bloody saw.
Evelyn seemingly dies in front of the others, strapped to an electroshock therapy table. Price pulls a gun on the guests, demanding to know who killed his wife. Eddie knocks him out and they lock Price in the "Saturation Chamber", an archaic zoetrope device that Vannacutt used to treat schizophrenics. Blackburn volunteers to guard Price. When the others leave, he turns the chamber on, leaving Price to be tortured by the moving images and ghostly hallucinations. In Vannacutt's office, Sara and Eddie find a portrait of the hospital's head staff and realize that the party guests are descendants of the five survivors of the 1931 fire. Pritchett deduces that the spirits themselves hacked the guest list on Price's computer. The only exception is Blackburn, whose name does not appear among the staff.
Blackburn is revealed as Evelyn's lover. They have faked Evelyn's death, plotting to frame Price for the murders, hoping one of the guests will kill him in self-defense. Evelyn heartlessly kills Blackburn, adding another victim, then releases a delirious Price from the chamber. Sara finds Price, covered in blood and with Blackburn's severed head nearby, and shoots him. Eddie and Pritchett arrive and bring Sara upstairs, after which Evelyn approaches Price to gloat. Price, protected by a bulletproof vest and posing as dead, attacks Evelyn. As they scuffle, Evelyn is thrown through a decaying door, revealing the evil core of the house – The Darkness.
The shape-shifting creature, composed of the spirits in the house, consumes Evelyn, adding her spirit to its mass. Price then discovers Melissa's body. Shortly after, Pritchett is also killed by The Darkness, allowing Price to flee. Price tells Sara and Eddie that the only escape is through the attic. The Darkness seeps through the house, following them. Price opens a window in the attic, then sacrifices himself to give the others time to escape. Sara gets out, but The Darkness closes an iron gate, trapping Eddie.
As The Darkness prepares to assimilate Eddie, Eddie reveals he is adopted, and not a true descendant of the original staff. Pritchett's ghost appears and opens the iron gate. The Darkness is distracted by Pritchett long enough for Eddie to escape. Pritchett's ghost and The Darkness fade away as Sara and Eddie watch the sun rise. They find an envelope on the ledge, containing all five checks, made out to cash.
In a post-credits scene, a black and white film is shown, depicting the spirits of the 1931 patients torturing the Prices for eternity.
Only logged in users may leave a review.