When the lifeless body of Eleonora Fontana, daughter of a renowned politician, is found in Bellinzona during the carnival, Commissioner Blum decides to set up a special team. The crime seems to have its roots in the past.

Recent threats against Eleonora's father lead Blum and his team to investigate the suicide of a famous industrialist. Until the discovery of a second corpse, whose stigmata recall the case of a ruthless serial killer.

Now that the link between the Rochat case and the murders of the young girls has been established, the investigators look to the past. They discover that Eleonora's father and Amanda's lover are two of the three witnesses to the former's suicide.

Secrets revealed after years of silence and a third horrific crime force Blum and his team to consider new leads and new motives, leading them to wonder if the events of 2012 hadn't happened as everyone has always said.

As Blum grapples with the ghosts of the past, the search for the Meiers takes a new turn. The team has no doubts: the father and daughter are at the centre of the avenger's criminal fury.

Although his identity has been discovered, the killer has no intention of stopping until he has carried out his revenge and delivered the final blow.