Professor Ayres obtains a tablet from an ancient Etruscan cave. He proceeds to hack at a cave wall, while a stone mechanism activates behind him. Turning around, he sees a skeletal zombie looming towards him and within seconds, several more catch him and eat him.A group of people arrive at the country mansion where Ayres is staying. They make up of couple Evelyn and George with their 13-year-old son Michael, and other couples Mark and Janet, and Leslie and James. That night, Michael pretends to be asleep and he walks in on Evelyn and George having sex, upon which Evelyn angrily shoos him away. Janet has a nightmare that something terrible will happen but Mark manages to calm her down.The next day, James and Leslie head outside to make out. Mark photographs Janet around the estate, while George shows Evelyn the artifacts that Ayres had unearthed from the caves. In the house, the butler Nicholas and the maid Kathleen witness several bulbs exploding due to some electrical interference.Meanwhile, the countless zombies emerge from the caves and into the countryside. While Janet and Mark make out, a zombie rises from the ground and grabs Janet. They both flee the zombies, as do James and Leslie when they witness one emerging from a stone crypt. Another few zombies encounter Evelyn, George and Michael in the cellar. George attempts to shoot them with his pistol, while Evelyn and Michael escape. They eventually overcome George where they rip him apart and devous his innards.Janets foot is caught in a bear trap in the garden, after which two zombies catch up with them. Mark is grabbed by a zombie and strangled, while the other zombie attacks Janet. James and Leslie arrive and kill the zombies by cracking their heads open with rocks. Evelyn and Michael are caught in the cellar, but Evelyn douses their attackers with flammable paint and sets them alight. All the survivors make it to the mansion and Nicholas lets them inside.Night falls and they barricade the windows and doors, while the zombies utilise the tools from an old shed. Mark sends Kathleen to make sure all the windows are boarded up upstairs but she finds one open. She goes to close it but a zombie throws a knife at her hand, piercing it and nailing it to the window. While screaming in pain, the zombies decapitate her with a scythe. James goes upstairs to the second floor and sees Kathleen's corpse, which he throws out to distract the zombies while he closes the window. The zombies meanwhile hack at the doors of the house with the tools. James and Mark open fire on them with shotguns they find in a closet, killing several of them by shooting them in the head. After a few minutes, with their numbers dwindling, the zombies retreat out of range.During this lull in the siege, Leslie goes to find bandages for Janet's foot but a zombie grabs her by the hair when she passes a window and pulls her towards the sharp edges of the glass, impaling and killing her. Janet is cornered when zombies break through one part of the house, and she repels them using a spear. James and Mark arrive to help her, while Evelyn defends Michael from some zombies with a long dagger. Eventually, they kill the zombies that are inside the masnion and barricade up the room.A while later, Evelyn tells Michael that she's sorry she brought him here, after which she is shocked when he makes incestuous sexual advances on her. She angrily slaps him and he runs away. He stumbles upon Leslie's corpse which reanimates and ambles towards him.Meanwhile, Janet sees the zombies in the courtyard gathering for a second assault on the house and Mark suggests they let them in and hide. Evelyn goes to find Michael, and spots Leslie's blood near the window. Following the trail of blood, Evelyn steps into a bathroom where she is horrified to see the zombie Leslie devouring a dead Michael's arm. After crying over his corpse for a moment, she madly attacks the zombified Leslie, bashing her head against the bathtub and killing the zombie.The zombies use a log as a battering ram to break through the front door, and the group flees upstairs. They hide inside a cupboard while the zombies amble to the top floor. A broken Evelyn joins them and they make their way out of the house. Nicholas falls behind everyone else and meets a zombified Professor Ayres on his way out. Ayres attacks him, ripping his throat out and eating his innards.The remaining survivors flee into the nearby woods and they decide to wait til morning before moving out. In the morning, the group spots a monk walking into a monastery and follow him. James attempts to find the monk and stumbles into a room full of monks, but they are actually zombies in shrouds who immediately kill and feast on James. Evelyn, Mark and Janet discover this and flee while James reanimates as a zombie.The three survivors of Mark, Janet, and Evelyn flee to a nearby architecture workshop and shove one the models in front of the gate. They are soon besieged by a stray zombie, while the rest of them attempt to break through the gate. Evelyn and Janet hold the gate closed while Mark dispatches the zombie by throwing him over a balcony. They attempt to escape but a zombie Michael appears and Evelyn is overcome with happiness, believing him to still be alive. Still regaining the desire, Michael exposes her breast but bites it off viciously, while more zombies pile in trapping Mark and Janet. Mark is grabbed by two zombies who force his head into a buzz saw killing him. George, now a zombie, arrives and feasts on his dead wife's face, while others devour her body. A zombified James joins the majority of the countless zombies who simultaneously reach for Janet. Janet screams as the zombies attack and kill her as well. Apparently there are no more humans alive in the area. The zombies have won."The earth shall tremble, graves shall open, they shall come among the living as messengers of death and there shall be the nights of terror."'Prophecy of the Black Spider'