This is a review of the audio version. I say that, because although the story was gripping, the narration was quite disconcerting. I couldn't tell if a character was supposed to be Scottish, Geordie or South African. A good try, but not quite there I'm afraid, so a star is lost just for the medium.
As regards the story - terrific almost all the way through, with great detailed character descriptions of the new people involved.
Just...I had sympathy for Paula's new DCI. You get clothing from a murder victim with an identifiable bloodstain, plus a mobile phone from a further victim carrying a fingerprint from the same person, and of course you haul them in, even if he's Tony Hill, consultant psychologist. Except that Tony Hill's girls (and they are all girls) cry 'No,that can't be true'and solve the case off their own bat, leaving egg on the DCI's face. Success or failure, I can't imagine any of them would have much of a future in any UK police force.
Apart from that - gruesome, but that's what we expect from Val McDermid. Chilling as well, which takes a lot more art - the details which emerge as to the culprit's upbringing and his father's marital arrangements leave you wondering about what happened to other characters apart from the main ones. As I said, it is a gripping story, but I felt that from the point where suspicion fell on the real culprit to the end, all the usual denouements involved in the tracing/following/capture were compressed into too small a space, as if the author felt taht enough pages had been written, so she should bring it to a close.