Rocca is faced with a case that seems to have to do with a satanic ritual. The discovery of a note inside a dead kitten with the inscription "Male returns healed" and, shortly after, the killing of a girl named Marisa, lead the Marshal to suspect a connection with the case of Professor Aleppi, of which he had occupied seven years earlier. In fact, the professor had been the director of an orphanage whose former pupils had founded a sect to avenge their deaths.