Murder Comes Calling — C.S. Challinor

When four murders take place in a secluded English community, Scottish barrister Rex Graves is called on by an old friend to lend his investigatory expertise. The authorities suspect a shady house agent, but letters written in blood on the bodies tip Rex off to a different kind of killer.

Digging into the past, Rex discovers that the victims were not who they appeared to be. For the first time, he's not up against a lone operator. With his fiancée away on a cruise, Rex must race to solve the murder before she catches him indulging his forbidden crime-solving hobby ... or before he becomes the latest victim.