A professional killer is at large in the cities of Italy. Code named "The Pit Bull" the killer is a master of disguise and an expert with weapons. He modifies his guns and his bullets are untraceable. His skill with prosthetics, wigs, makeup and padding means that no two victims witness the same before their death and, as with the search for the ever-reincarnating "Iguana" in Almost Blue, once again this is a hunt for a man with no face. Only the picture of a pit bull terrier, from which the killer takes his name, left behind at each murder can link the crimes. Stuck in a rut, the Pit Bull's life continues, day after day. And, day after day, Ispettore Negro works on her seemingly impossible case. When an innocent young man, surfing the Internet, unwittingly places himself in serious danger from the Pit Bull, Negro uses the man's knowledge of cyberspace to help her close in on her terrifying target.