A Perfect Blood
by Kim Harrison is the tenth novel in 'The Hollows' series. Those familiar with these books already know about Rachel Morgan, the witch who has a vampire roommate named Ivy, a salty-tongued pixie colleague named Jenks and a plethora of other intriguing beings who are sometimes allies, sometimes enemies and occasionally both. This fascinating series addresses sometimes uncomfortable themes but is never boring as the reader watches Rachel work through her angst about the choices she has made in her life. This novel follows Rachel as she searches for a way to handle life without being able to access most of her powers even as she continues her stubborn refusal to comply with the expectations of those around her. A series of horrific murders seem to imply that someone is conducting terrible experiments searching for a particular genetic component and Rachel and her colleagues become involved in the investigation which may become much more personal than they would like. My Goodreads review is at this link.
If you are indeed new to the series, the first title is Dead Witch Walking and introduces Rachel just as she is meeting Ivy. It's a great series and you are in for a treat but I warn you that there are definitely highs and lows and occasionally I have wanted to shake some sense into Rachel.