Ghost Writer by Steve Higgs
In the nation's Capital, someone is re-enacting the murders from a series of grisly horror books, and all the evidence points towards the author as the perpetrator. The big problem with that? He died a year ago. In suspicious circumstances. There were rumours of murder, but no arrests followed the original investigation. Now the victims are those who were closest to him, and it looks like the author has come back from the dead to exact his revenge. Hired by the author's wife, who fears she may be next, Amanda and Tempest head to London for a case that will challenge the premise on which their business is built: that the supernatural does not exist. You're going to want to sleep with the light on. The paranormal? It's all nonsense, but proving it might get them killed.