The Blood Detective Nigel Barnes Series, Book 1.

As dawn breaks over London, the body of a young man is discovered in a windswept Notting Hill churchyard. The killer has left Detective Chief Inspector Grant Foster and his team a grisly, cryptic clue... However it's not until the clue is handed to Nigel Barnes, a specialist in compiling family trees, that the full message becomes spine-chillingly clear. For it leads Barnes back more than one hundred years - to the victim of a demented Victorian...