I enjoyed this book. The premise, that a cure has been discovered for serious illnesses that leaves the patient with vampiric characteristics as a side effect was intriguing.
I also liked the main character, prickly Nick Guthrie a gay police officer and 'Vee' who has some issues around forming personal relationships. The intricate dance that is the development of his relationship with Dr Anton Marber was, for me, the main pleasure of the story.
The main reason for the comparatively low rating is that the actual crime story never seemed very real or plausible to me. We didn't get to know the victims, so the murders had little emotional impact, and I was only semi-convinced when the identity of the perpetrator was revealed. I might have found it more plausible if more information and background detail had been leaked throughout the narrative, but it felt rather as though the reader was being asked to take quite a bit on trust, just as we were told who the killer was.
Part of the problem, I suspect, is that this novella was more strongly focused on the detective's personal relationship, so that the crime element took a back seat. There wasn't enough space for a convincing romance and crime drama combined.