Coyle and Fang: Curse of Shadows by robert adauto III

SPSFC

The year is 1892. A mythical book has been stolen, and the fate of mankind rests in the hands of two exceptional women: a brilliant detective and a deadly vampire. But they discover things are never that simple as they face a world much more dangerous than either could have imagined. Between enemies within and enemies without, can Coyle and Fang stop a madman before it kills hundreds of thousands?