Can they be stopped?

Five friends are enjoying dinner on their first evening at a ramshackle but cosy enough log cabin in the Tennesee Forest when all of a sudden in the next room - BANG! The friends find that the trapdoor to the cellar has mysteriously opened. Peering into the cold, bleak and pitch black void, they dare each other to investigate. Scotty braves the ricketty stairs first and disappears without a sound.
When after a few minutes Scotty doesn't answer his friends' calls, Ash follows. There's no sign of him in the gloom, and something screeches at Ash. Phew! It's only Scotty, pulling his leg. Scotty leads Ash to a dim corner of the cellar, where a sinister pile of possessions of the former owner begs to be examined. There's a long dagger - it's hilt carved into skulls, an audio tape, and a small but gruesome book, bound in human flesh and inked in blood...

Back upstairs, Sheryl protests in vain when Scotty plays the tape. The voice of the previous occupant of the shack, explains the significance of the Necronomicon (The Book of the Dead) and the dagger of the dead. The eerie voice proceeds to read the text of the book - a deadly incantation with horrific consequences...