The Cellar is Richard Laymon's debut novel as well as the first part of the Beast House trilogy. It was first published in 1980.
Visitors flock to see the Beast House with its blood-soaked corridors and creaky doors. Armed with Instamatics and video camcorders, these poor souls enter the forbidden house, never to return. The deeper the tourists go into the house, the darker their nightmares become. The men are dealt with quickly. The women have to wait longer...first they are tortured and sexually ravished. But the worst part of the house is actually beneath the haunted structure. There lies even a more terrifying presence waiting for its next victim. Don't even think about going into the cellar...
In the prologue, a police officer named Dan Jenson is investigating the local tourist attraction known as the Beast House. He suspects that there is a prowler inside, but in reality it's just a boy and his father trying to be adventurous. The two are then attacked by an unknown assailant. When Jenson hears this he breaks in, only to find himself at the mercy of a bloodthirsty horror.
Donna Hayes hears that her psychotic ex-husband has been released from prison. Remembering the horrific things he did to her and their daughter Sandy, the two of them run away from home. Their car breaks down in the middle of nowhere and they're surprised by large, sinister man. Frightened, Donna knocks him back with the car door, only to send him into a ditch. Feeling bad, she checks on the man and it turns out he's not a psycho, just mentally disabled. The man says his name is Axel Kutch and his family owns a local tourist attraction in Malcasa Point known as the Beast House. When a tow truck arrives to carry off their car, Donna and Sandy follow Axel to Malcasa Point and book a cabin.
Donna's husband Roy arrives at their place only to find out that they've given him the slip. He goes to the neighbours' house hoping to get some answers but his aggression gets the better of him and he kills the couple. Noticing that they have a 9-year-old daughter named Joni, he decides to take her with him, but not before raping her. Roy then goes to see Donna's sister Karen, torturing her for information before killing her. Now knowing that Donna and Sandy were heading to Malcasa Point, he makes his way there with Joni in tow.
Judge Rucker is a trained assassin who has been hired by a man named Larry Usher to investigate the recent killing in the Beast House, remembering his own encounter with the creatures which he asserts are very real. As soon as they arrive in Malcasa, Judge and Larry run into Donna and Sandy. Donna and Judge are instantly attracted to each other. The four then go to the Beast House for a tour. The host, an elderly woman by the name of Maggie Kutch, tells the story of how the titular beast has been preying on the house's inhabitants for decades. She nonchalantly mentions the grisly murder of her own family, as well as the death of Larry's boyhood friend while remarking that Larry abandoned his friend to the beast. Incensed, Larry storms off.
Judge and Larry book a cabin neighbouring Donna's and Sandy's. Not thinking that the beast is real, Judge decides to break into the Beast House at night and find some answers. He's attacked by someone or something and barely makes it out. Donna, fearing the worst, arrives in Larry's cabin and finds Judge in the bathroom tending to his wounds. The sight of Judge alive and well after such a dangerous experience arouses Donna to the point where she has sex with Judge right there on the bathroom floor, completely ignoring the fact that Larry is just outside and Sandy is all alone.
Roy arrives in Malcasa with Joni in tow. He sexually abuses her any chance he gets and kills anyone who might threaten his freedom. Booking a cabin, he manages to get the cabin owner's daughter Janice alone and rapes her as well, leaving her trapped in his room.
Judge takes the Beast House tour a second time and manages to get his hands on a journal belonging to the house's original owner Lilly Thorn. At Donna's cabin, they read what initially starts out as a love story between Lilly and her future husband. After the two buy their first house and start a family, Lilly's view of her husband becomes much less affectionate. Donna reads on and discovers that when Lilly noticed that their cellar had been raided, she ventured down there one night in the hopes of catching the culprit. To her surprise the thing in the cellar was a naked humanoid creature. The creature tore off Lilly's nightgown, forced her on all fours and proceeded to have sex with her. What was most shocking was the fact that Lilly enjoyed every moment of it, desite being left bruised and bloody afterward. It's explained that the sex she had with the beast was so good that her husband could no longer satisfy her, hence her sudden indifference. The last part of the journal mentions that Lilly decided to let the beast run free in their house, killing her husband and their children so that she could be alone with her monstrous new lover.
As Donna reaches the end, Roy bursts into her cabin. Judge manages to get the upper hand on Roy and instead of reporting him to the police, decides to feed Roy to the beast.
At the Beast House, Judge, Donna and Larry leave Roy tied up as live bait. A beast then appears before Roy, but the others are too busy running for their lives to witness Roy's death. Larry is attacked by one of the beast's siblings and thrown out of a windo to his death. Donna finds herself cornered by Axel, who tries to rape her. Donna kills Axel, but instead of escaping, goes after Judge. Sandy follows them after seeing Larry's corpse. Judge ventures into the cellar, discovering a tunnel that lead into the neighbouring house. Once inside he sees that the original beast has spawned a whole family that Maggie Kutch routinely has sex with. Judge kills all but two of them, before being stabbed by Maggie.
Janice and Joni escape and befriend each other, neither one ready to forget their horrific ordeals. Donna and Sandy are now prisoners of the Kutch family, used as sex slaves for Maggie's beast-sons. Donna and Sandy both enjoy the sex as much as Lilly did, though Donna still wants to escape. It's revealed that Donna's pregnant, but it's unknown if the baby is Judge's or one of the beasts.
- It's mentioned in the sequels that The Cellar is set in 1979.
- Dan Jenson is later revealed to be the estranged boyfriend of Tyler in The Beast House.
- It's unknown what happens to Joni after this as she's never mentioned in the sequels. Presumably she was sent to live with a foster family.