The Whateley family has always been an object of scorn and dread. When Lavinia Whateley gave birth to her twin sons, some locals conjectured that the family patriarch, Zechariah, was the natural father. Drs. Walter Rice and Fay Morgan team up with their former mentor, Dr. Henry Armitage, to battle the Whateley clan before they can unleash the demon, Yog Sothoth.

Based on the famous Lovecraft story, The Dunwich Horror stars Dean Stockwell and Jeffrey Combs. Dean Stockwell starred in the original Roger Corman version of The Dunwich Horror as Wilbur Whateley. He now stars as Dr. Henry Armitage while Jeffrey Combs, of Re-animator fame, takes up the Whateley mantle.