Carey, Mike -- The Devil You Know
An exorcist tries to make rent in an alternate London where the ghosts
all came back one day. (I think it was one day, I've forgotten the exact
scenario.) The secrets of dead people turn out to be squalid, dark,
morally unfocussed, or -- in a word -- noir, which makes this a great
setup for a Harry-Dresden-style investigative paranormal series.
Books I have acquired recently
All the books I own