Centuries ago John D'Ampton slayed a giant snake-like demon that was menacing a small town in England. It's now present day and a local archaeologist Angus Flint excavates a skull that was part of the worm. The skull is excavated on the property of James D'Ampton, a descendent of John D'Ampton. The property is home to two orphaned girls named Mary and Eve Trent, whose parents disappeared without a trace.
Lady Sylvia Marsh, a neighbor to the Trent family, recently arrived back at her home. Sylvia steals the excavated skull from the Trent home. There's more to Sylvia than meets the eye; she's part of an ancient cult that worships the worm as a god and believes the worm is still alive, but is trapped somewhere inside of a local cavern. The followers of this cult are part snake and part vampire. They spit poisonous venom and are capable of paralyzing or transforming their victims after a lethal bite which injects the poisonous venom.
Sylvia plans on using the skull, along with a virgin sacrifice, to free the creature from its imprisonment. When Eve disappears, James, Mary, and Angus must find her before she sacrifices Eve.
When the worm saw Eve it started crawling in the hole of the cavern to eat her. Sylvia almost cut the rope that was holding Eve but Angus push Sylvia and drop her to the cavern right into the worm's jaws. He rescued Eve but the snake almost reached the surface to stop it he threw a grenade into it's mouth. Blowing the ancinet demon to pieces.