Helen Mallory is a beautiful young woman who has been unable to speak a word since seeing her husband and daughter die in a fire. She visits the home of her elderly, invalid grandmother, and meet her uncle, Joe Sherman, a respected psychiatrist, but the visit turns into a nightmare as she encounters his brash brother Steven, a pretentious Southern belle named Blanche, and a number of other mysterious characters in a house where everyone's life seems to be in grave danger.