A triple murder case involves a man with a mysterious identity and two prostitutes who seem to be victims of an exemplary revenge. A series of corpses begins to emerge from the fog, in a Milan tight in the grip of frost.

The spectre of a serial killer hovers over the city and Chief Inspector Alessandro Rossini finds himself confronted with a complex and dangerous investigation, embarking on a journey into the darkest  sides of organized crime.

While the truth struggles to emerge in front of him, old stories that seemed now buried return to visit him, bringing with them ghosts of the past and doubts about the present. Suddenly, what appeared to be trusted friends become unsuspected enemies and Rossini is alone fighting against an enemy without identity.

When even his private life is turned upside down and he is about to lose everything, Rossini knows that only discovering the truth will save him.