A dangerous magic

Frank Sampson is fifteen, yet he already works as a magician who investigates crimes by reading traces of sorcery. When the Bishop of Oxford is found dead, the case falls to him. Progress is slow. The bishop's niece, Kazia, is lovely but far from cooperative, and Frank must also work alongside Marvo, a colleague who is hard to get along with. Frank's trade is governed by a long list of regulations that shape every step he takes.