October 1st 1862, thirteen persons are stabbed at the same time in equidistant different points in the city of Palermo. Attorney Guido Giacosa is in charge of these multiple crimes investigation. He has just arrived in Sicilia after been appointed General Prosecutor at the Palermo Court of Appeal. He's committed to find the true instigator. The first suspect to confess his guilt is Angel DAngelo, and others will follow; however, the mastermind is elusive and hard to catch.