The Bastard King

From publisher blurb: In the last months it seems a strange "epidemic” of suicide has taken over Paris, the authorities are trying to ignore it, but a small disturbing detail can't be overlooked forever: The corpses of the afflicted were all marked by the same strange sign. Some call it the Sign of the Bastard. Its connection with a famous operetta titled The Bastard King will lead the characters down a road paved by peril and madness. Can they stop the Bastard King before becoming his next victims?