First Mo Hayder thriller in the Jack Cafferey series. Gruesome, gripping, nailbiting and cruel story. Very fast paced. To me, this is more a horror book than a thriller and towards the end, I found the continuous brutal abuses, tortures and ultimate murders exaggerated and often on the edge of credibility. Still, the story is never boring, keeps the reader hooked on the story till the final page. 3,5 stars for me. I would have assigned a 4 * rating but felt that the endless abbreviations of police terminology had a negative impact on the reader's grip of the story, especially in the case of a non-UK resident reader.