An American writer traveling in Rome is the only witness to an attempted murder by a sinister man in a raincoat and black leather gloves, though he is powerless to do anything to stop him. With a feeling that something is not quite right about the scene he has witnessed and the police"s inability to make any progress, he launches his own personal investigation and nearly loses his life in the process. While this modern day Jack-the-Ripper type is slithering through the dark byways of Rome slicing up pretty girls.