A young, married business woman is found stabbed to death. The ensuing investigation suggests the woman may have been having an affair with a co-worker. Later, the detectives learn the woman was not having an affair, but was, instead, the object of unwanted attention from the co-worker. Her admirer has killed her as a result of his fetish for stabbing women (piquism). The warped fetish resulted from the man's incestuous relationship with his overbearing mother, the woman who continues to dominate his life.