Lothar Schramm is a simple man with complicated difficulties who appears to be a good guy. He is a cab driver who lives alone and is content to open his door to strangers and murder them. He has a difficult time dealing with women, like many timid loner types, so he poisons them and photos their naked bodies for sexual stimulation. So goes the life of a deranged serial killer: he murders his hapless victims, and so on.