Husband and wife parapsychologists Lee and Claire Marshall nearly crash their car in the woods after barely avoiding an insectoid monster darting across the road. A search for help leads to a derelict house and its bizarre inhabitants; brothers Bart and Mart, once twins until Bart began mutating into a glowing green monster, and their "Maw", a tyrannical harridan who, due to a glitch in the time vortex, is half the age of her sons. This bizarre family hides a secret, and eliminates any strangers who threaten to uncover it. Lee and Claire's attempts to escape leads them through a "Dead Place" teeming with bizarre creatures and a final, horrifying encounter with the alien source of all these mysteries.