Also known as Monster of Terror, this British-made horror opus is very loosely based on H.P. Lovecraft's story "The Colour Out of Space". The story begins with an American scientist (Nick Adams) paying a visit to the remote estate of his fiancee's family (located in Lovecraft's fictional Arkham County, Massachusetts) and finding many of the surrounding flora and fauna horribly mutated by strange radiation. The source of the contamination is discovered to be a glowing meteorite kept hidden in the basement by his girlfriend's father (Boris Karloff), who has been using the radiation to mutate local plant life. As one might expect, the experiment has gotten a bit out of hand... and poor mommy has changed into something unspeakably horrible.