The Unnamable

In the Winthrop house, a scream and banging echo through the dim corridors as Joshua rushes along and unlocks a heavily locked door. He speaks calmly to the creature inside in a bid to soothe her, but Alyda, the demon daughter, overpowers him and kills him. The moment establishes the house's deadly secret and Alyda's power.

Randolph Carter regales his university friends Howard Damon and Joel Manton with tales of Joshua Winthrop and his demon daughter Alyda in the graveyard surrounding the haunted house. He notes that the house lies within the limits of observation, setting a boundary for their legends. Joel suggests they stay overnight to witness the stories in person.

After Randolph and Howard depart for the university, Joel remains alone in the Winthrop house. He decides to test the legends by spending the night among the haunted corridors. The choice places him on a collision course with Alyda's return.

Bruce Weeks, John Babcock, Wendy Barnes, and Tanya Heller arrive and set up in a room to tell each other ghost stories. The ominous atmosphere suggests they are not alone as the house seems to close in around them. Tension rises as flirtations give way to fear.

Howard chases Randolph to tell him that Joel never came back, turning curiosity into urgency. Randolph responds with determination, promising to bring flashlights and investigate. The search for Joel quickly becomes a matter of survival.

Alyda Winthrop, the demon daughter, begins stalking the four students, planning to kill them as she killed her father and Joel. The danger grows even as they continue their storytelling. The threat behind the walls becomes imminent.

The group discovers Joel's decapitated corpse, hanging upside down, with his head rolled onto a plate and blood staining the floor. Wendy glimpses the grisly sight, and fear grips the room. The grim discovery confirms the demon's lethal reach.

Randolph and Howard arrive to find the door has locked itself, which he interprets as magic at work. He consults the Necronomicon and finds a spell to unlock the door, then goes outside to descend into the ground via Joshua Winthrop's tomb under a tree. The occult plan sets the stage for a direct confrontation with Alyda.

In a climactic turn, the tree under Joshua Winthrop's tomb, aided by Randolph and the Necronomicon, snatches Alyda out of the house and drags her away. Howard and Tanya watch in terror as the immediate threat is removed. The escape marks a turning point in the struggle.

Howard and Tanya flee to a safe distance, but a hand emerges from the ground and pulls Howard down. Randolph rises from the catacombs beneath, having fended off skeletal guardians. The final standoff leaves the survivors wary about what else might lurk beneath the house.

Randolph surfaces from the catacombs, having survived the subterranean ordeal and the skeletal guardians. The night ends with Howard and Tanya alive, Alyda taken away, and the threats of the demon seemingly contained for now. The survivors are left to confront the eerie calm that follows the storm.