Synopsis: One quiet night, on a university campus, a teacher is waiting for the last three students to finish and hand in their exams when they realize they are closed. Suddenly, a group of killers, dressed as medieval black plague doctors and armed with knives, enter the room in search of victims. The next morning, the police find the corpses forming a kind of macabre art. Who could have done it? Who would be able to do such a thing and why?
The one in charge of answering these questions is Mara Monti, an experienced and rigorous Prosecutor who has been disappointed time and time again by the judicial system and who will now, through this case, seek to obtain the recognition she deserves and thus be appointed Attorney General. However, some time later, Monti will have to answer to proceed before his immediate superior, Chamber prosecutor Pablo Gandolfo who will put on the table the contradiction on which the investigator is immersed.