The Bone Magician by F. E. Higgins
The Silver Apple Killer preys on the people of Urbs Umida, a rotten and wretched city. Two things connect the victims - they all had a small silver apple in their pocket, and they had all recently visited a notorious inn to see one of two acts: the hideous Gluttonous Beast and the astonishing Bone Magician . . .
Since his father disappeared under a dark cloud of scandal, Pin Carpue has been alone in the world. His work for the local undertaker keeps him busy, but his life is bleak. Then Pin encounters the Bone Magician, a man who can raise corpses and make the dead speak.
As Pin is drawn into an intoxicating world of mystery and intrigue, he becomes suspicious of Juno, the Bone Magician's young assistant. A strange darkness haunts her just as the Silver Apple Killer stalks the streets at night - and as Pin pieces together the secrets of Bone Magic, his own life becomes fraught with grave danger . . .