Villian(s)  Deranged man

Actor(s):  Stephen Furst, Sydney Lassick, Barbara Bach, Karen Lamm

Brief Description  The Unseen (1980) is an American psychological horror and slasher film directed by Danny Steinmann (originally credited under the pseudonym Peter Foleg). Based on an original story co-conceived by legendary makeup effects artist Stan Winston, the film has gained a cult following over the years for its unsettling themes and claustrophobic atmosphere.

Plot:
The story follows freelance television reporter Jennifer Fast (played by Barbara Bach) and her two friends, Karen and Vicki, who travel to Solvang, California, to cover a local Danish festival. Because of a massive hotel booking mix-up, the women find themselves completely stranded with nowhere to stay. They accept a generous offer for cheap room and board at a large, isolated farmhouse owned by Ernest Keller (Sydney Lassick), a friendly but eccentric local museum owner who lives with his withdrawn wife, Virginia (Lelia Goldoni). Unknown to the visitors, the Kellers are harboring a dark, unspeakable secret. Locked away in the basement is a hostile, intellectually disabled man-child named "Junior" (Stephen Furst).

Junior is the product of a hidden incestuous relationship between Ernest and Virginia, who are actually brother and sister. While Jennifer is away trying to resolve a relationship dispute with her ex-boyfriend, Junior escapes his confinement. One by one, he begins to terrorize and brutally murder the women through the farmhouse's floor vents, pulling them down into his subterranean lair. When Ernest discovers the slaughter, he decides that Jennifer must also be eliminated to prevent their horrific family secret from being exposed to the world.