The head of a now abandoned asylum, Dr. Richard B. Vannacutt (Jeffrey Combs), once performed grotesque experiments on the patients, killing many in the process. The hospital was closed in 1931 after the patients escaped from their cells, killing the entire staff (except five who were not present) and setting fire to the hospital. Vannacutt had rigged the building with numerous iron gates, activated by cranks and levers that cannot be reset for twelve hours, to keep patients from escaping. He closed the gates during the fire, dooming the patients and himself to death. Decades later, during reconstruction of the facility, several unexplained deaths result in the building being dubbed "The House on Haunted Hill".In 1999, Evelyn Stockard-Price (Famke Janssen), a spoiled trophy wife, is in a disintegrating marriage with Steven Price (Geoffrey Rush), an amusement park mogul with a wicked sense of humor. Price leases the house from the owner, Watson Pritchett (Chris Kattan), for Evelyn's birthday party. Evelyn gives Price a lengthy guest list; he shreds it to spite her and then creates one of his own. Five guests arrive for the party - Jennifer Jenzen (Ali Larter), Eddie Baker (Taye Diggs), Melissa Margaret Marr (Bridgette Wilson), Dr. Donald Blackburn (Peter Gallagher), and Pritchett himself. The guests are not the ones Price invitedâneither Evelyn nor Price know who they are. Despite this, Price continues the party's theme, offering $1 million to each guest who stays in the house and survives until morning, with any person not making it having his money added to the pot.The security gates are tripped, locking everyone inside. After finding some hand guns, Jennifer, Eddie and Pritchett decide to take one of the guns. Meanwhile, Price scolds Carl Schecter (Max Perlich), a company employee - who has developed a series of harmless traps to scare the guestsâ for not letting him know he planned to pull a stunt like closing the iron gates. When Schecter states that he is not responsible, Price believes Evelyn is responsible. Meanwhile, Pritchett, Eddie and Jennifer go into the lower levels to find a way to open the gates. As Eddie and Jennifer explore the dungeon-like basement, Jennifer confesses to Eddie that her real name is Sara Wolfe, and that she's an out-of-work assistant to the real Jennifer Jenzen. And that she attended the party in Jennifer's place because she needed the prize money. However, the two are separated, and Sara is nearly drowned in tank of blood by a ghost impersonating Eddie. Though the real Eddie arrives in time to save her.Melissa disappears when she wanders off in the basement, leaving behind a massive trail of blood. After Melissa's disappearance, Price goes to Schecter to accuse him of faking the killing and hiding her; when he turns the seat around Schecter is found brutally murdered. Price sees a doctor walking through the room with a bloody knife on a surveillance monitor and fruitlessly chases after him. Shortly after, Evelyn dies in front of the others, when they find her mysteriously strapped onto a hypercharged electroshock therapy table. Furious, Price pulls a gun on the guests, demanding to know which one of them killed his wife. Sara nearly shoots him, but Eddie knocks him out before either one can kill the other. The remaining guests lock Price in the "Saturation Chamber", an archaic device that Vannacut used to treat schizophrenics. Blackburn volunteers to stay behind to guard Price, while the others search for another way out. Seemingly clueless as to what the machine is or how it works, Blackburn turns the chamber on with Price still inside, and leaves him trapped. The chamber bombards Price with moving images and ghostly hallucinations until it drives him catatonic.Meanwhile, Sara and Eddie find Vannacut's office. Inside, they find a portrait of all the head staff, most of which have their last names, as well Price's and Evelyn's maiden name, on a staff picture from the asylum. Pritchett explains that the spirits themselves created the guest list specifically to include the descendants of the five members of Vannacutt's staff who did not die in the 1931 incident. The only exception is Blackburn, whose name does not appear amongst the staff.Blackburn is revealed as Evelyn's lover and they are working together to kill Price. Evelyn, who was brought back to life by Blackburn, kills him and uses his body to frame her husband. Sara, who heard Melissa moaning in the basement, comes across an incoherent Price in the basement, still delirious from his "treatment" in the saturation chamber. Believing that he is Blackburn's murderer, shoots him as he begs her to help him. After the others return upstairs, Evelyn approaches Price to gloat, and Price, protected by a bullet-proof vest, attempts to kill Evelyn. The two scuffle before Price throws her through a decaying door. Inside the rotting room, the two realize they just stumbled upon the evil core of the house. The Darkness â a dark, shape-shifting creature composed of the spirits in the house â awakens and begins to take form. Evelyn is captured by the Darkness, which assimilates Evelyn into itself, killing her while Price watches in horror.The Darkness emerges in front of Price, revealing that it is composed of "everyone who died and is responsible". This force begins to pursue Price. Pritchett is killed by The Darkness, allowing Price to evade it. Price tells Sara and Eddie not only that Pritchett was right, but the house really is alive and deduces that the only way to get out is through the attic. The three flee as The Darkness begins to seep through the house, manipulating the walls and shattering the floors as it chases them.As they flee, Sara trips, and the Darkness uses Melissa's form to try to lure her to it. Price activates a pulley that reveals an opening in the window of the attic. When the Darkness seeps into the attic, Price sacrifices himself to give the others time to escape, but the Darkness reactivates the iron gate after Sara escapes, trapping Eddie inside.When The Darkness confronts Eddie about his ancestor's actions, it takes on several forms of all the guests who died during the party. Eddie screams out of desperation that he was actually adopted. As the Darkness prepares to assimilate Eddie, Pritchett's ghost appears and opens the iron gate. The Darkness is distracted by Pritchett long enough for Eddie to escape out the window to Sara on an outside ledge. Pritchett's ghost and the Darkness then both fade away. As Sara and Eddie watch the sun rise, they notice an envelope on the ledge. It contains all five $1 million checks, made out to cash.After the credits, a black-and-white film shows the patients torturing Evelyn and Price in the afterlife.
Output: Question: How many checks are in the envelope?, Answer: five