After several years in an insane asylum, Evelyn, the keeper of the Mountaintop Motel, is released and resumes doing business. She kills her young charge out of anger, but convinces the police it was an accident - and pushed into insanity, she then proceeds to target her guests, first by releasing vermin into their rooms, but then by using her trusty sickle.

When the word gets out of a mysterious Bigfoot-type creature, two researchers come to a small town to study and hopefully discover the true nature of the beast. With some help from the locals, the two men to learn that the creature may be a very angry and murderous missing link.