I believe some of peter James's pre-Grace books are more of the supernatural kind, but I haven't tried any yet. I do enjoy his use of the psychics in the Roy Grace series and how he tries to keep it secret. He's such a nice bloke too, I like to hear him on Mayo when a new book is coming out.
I'm not sure about the Shadow Walker though, it's getting a bit of a slating on the book group, but I still say I enjoyed it very much. Will be interested to see what you think.
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