The Thirteenth Day Of Christmas

Comfortable couple Gilbert Smith and his wife Evelyn are trying to enjoy an evening of post-Christmas cheer with friends Bill Norton and his wife Meg. Playing cards and enjoying their drinks, the group is interrupted by the appearance of Richard Smith, the Smith's mentally disturbed son. Initially trying to placate him, the group quickly realizes that Richard is totally unbalanced and perhaps even dangerous. With the Nortons bowing out for the evening, Richard is left alone with his parents, who quickly realize Richard is in far worse shape than they realized. Tragedy strikes, and more horrors await the Smith's daughter, Julie, who is expected home late from an evening date.