A prostitute is at a client’s house. During his sleep, he says incomprehensible things… While the girl is leaving, she discovers by chance some edged weapons and a light blue folder with some newspaper articles about past murders. She is shocked, grabs the folder and runs away. But the killer follows her and reaches her on the train that should take her home. After brutally killing the prostitute, the killer also murders her friend who is waiting at the station car park. The police start the investigation and discover a first clue: it seems that before dying, the girl has confusedly mentioned something about some crimes…