The recent threats addressed to the victim's father lead detective Blum and his team to investigate the suicide of an important industrialist. At least until a second corpse is found, presenting traces attributable to the case of a ruthless serial killer who died eleven years earlier.
During the traditional carnival celebrations, the dead body of a young girl is found near the small town of Bellinzona, in Southern Switzerland. The officers engaged in the case find themselves investigating crimes rooted in a past full of shadows.
