Suburbanites using a Ouija board in an abandoned shack set free a monster who prowls the caves under their neighborhood and materializes in living rooms to kill people.
Homes in the area are starting to show structural damage. So a group of spelunkers - including two of the people who unleashed the monster - go into the caves to see if local mining operations have been drilling under their homes.
Well, get ready for a collision course with a killing machine as the group runs into the monster and runs about in the caverns. The monster on the cover is what it looks like, so that should tell you what you're getting into - and why are adults in an abandoned shack with a Ouija board? They can do that in their own home.