"The Dark Other" by Stanley G. Weinbaum is a horror novel written in the 1920s and published in 1950. Patricia Lane falls in love with Nicholas Devine, a gentle writer who undergoes terrifying transformations, becoming cold and menacing. When Devine's sudden personality changes escalate into violence, Patricia seeks help from psychologist Dr. Carl Horker. What follows is a chilling mystery that blurs the line between psychological horror and the supernatural, leading to a shocking medical discovery. (This is an automatically generated summary.)