It is my third review of a Dominic Grey book and, although the novel is a perfect standalone, I do recommed reading the previous installments. All of them feature the Czech religious phenomenologist Viktor Radek and his resourceful colleague, Dominic Grey. Think Sherlock Holmes and Watson, but in the Grey series, Sherlock prefers absinthe to cocaine, and Watson is an expert in jujitsu and lock picking. First two novels were self-published and very well-received. Personally I concidered them one of my best indie finds when it comes to paranormal thrillers. Now the author got a publishing deal with Thomas & Mercer - I admit I was curious whether it made the next installment better or worse, with the author enjoying (hopefully) a professional editorial help.The Diabologist is a novel about two things - the nature of belief, and the dichotomy of good versus evil. Yes, it's a rip-roaring, pulse-pounding adventure, but actually I loved the most parts dealing with philosophical divagations about the concept of evil, and how it's defined (or justified) within the bounds of faith and belief in our society. It all begins with the mysterious deaths of two prominent religious figures but do not let the adjective 'religious' fool you - one is the head of the House of Lucifer and the other of the Church of the Beast. Both are condemned as heretics by an unknown magus and burnt. It turns out the public perception of a 'Satanist' is just as troubled and diverse as that of a 'Christian' faith and our two protagonists must navigate that maze in order to find the culprit because a murder is still a murder even if the victim had a rather unsavoury (and fully deserved) reputation.The best, absolutely best parts of this novels are closely connected to professor Victor Radek, a 60-year-old Czech gentleman who loves absinthe a bit too much for his own good and is a religious phenomenologist. Every time he entered the scene, either reminiscing about his past or dealing with the ugly present, the whole book got more intelligent and interesting. He had so many awesome things to say about so many topics: Zoroastrianism, the cults of Satan and/or Lucifer, definition of good and evil, theodicy (so divagations how come evil exists in a world created by a God who is an epitome of goodness and fairness) and whether real magic, black or white, exists.The parts narrated from the pov of Dominic Grey were not bad either (he is the kick-ass guy who used to live in Japan so small wonder) but here I can repeat practically everything I wrote before: time and again I caught myself wishing our sweet hero had a bit more sense of humour, that healthy irony and distance which make people, real or fictional, so likeable. Unfortunately in this novel Dominic sounded as dour and boring as in the previous ones; sometimes simply boring, from time to time even stupid but never ever funny. There wasn't any other character provided for the balance and I wonder why. Would it be so difficult to make our Dominic fall for a moderately cheeky, funny girl, full of ironic wit? And as I've already mentioned falling in love...Anka, the Romanian beauty by his side, was my biggest disappointment and, in my opinion, the weakest character of this installment. In fact I think she is the weakest female character written by Mr. Green so far - mind you the previous two were hardly great. My main complaint? Apart from other things Anka sounded simply artificial. I felt as if the author, not knowing what to do, gathered several incongruous traits, threw them in together, shaked a bit and hoped they would result in an interesting female. Unfortunately they didn't want to glue together.Ok, so we have a girl from Romania, a homeless orphan to boot, who feels in the UK at home and speaks fluent, idiomatic English. She says it's because she was raised by English-speaking nuns in an orphanage until her super-powers kicked in and she was proclaimed a devil worshipper and thrown out. Oooo-kay. Still it was just an orphanage…and she never mentioned how many years she spent there.Then allegedly she moved to a small town and found a post of a librarian (sic! without practically any education!). During that time she self-taught herself a lot about occultism and other paranormal abilities (because small-town libraries, Romanian or otherwise, have so many occult books on their shelves, right?). And, of course she polished her English (speaking and practising with whom, I pray? A butcher? A baker? A homeless drunkard?). Mind you Anka was very beautiful, simply stunning, even compared to those elegant, pampered London ladies (and I do beg the author to show me where he found such ladies in London) but until one evil man called Simon (or Darius) Azar nobody got interested in making use of exceptionally good appearances of that girl. No goody-goody stranger, no mafia, no neighbour pimp, no model agency, not even a hopeless romantic. Were they completely blind?Finally the ending. It was the silliest, most schematic and Dan Brown-esque part, especially with Anka being disqualified from the position of a Dominic's girlfriend because a) she lied to a complete stranger about her role in a certain cult (how dared she, this stranger being Dominic himself!) b) she killed with a knife another character (not saying who because it would be a spoiler, let me just assure you he was one manipulative jerk) looking remarkably ugly during the act c) she was manipulated, probably even coerced, by a sociopathic cult guru into having sex with certain individuals while being videotaped (how dared she!). *Le sigh*Still I loved some of the settings - Paris catacombs! Sicily! Cambridge! London!Final verdict:One of best occult thrillers I've read this year. If Dan Brown was able to write such a book he would crow about it for the eternity and award himself a medal. It was fast-paced and decently researched, fully enjoyable despite its flaws.