Dexter in the Dark by Jeff Lindsay
Once again we join Dexter Morgan and his journey through life as a serial killer vigilante who works for the police. This particular book centered around Dexter's dark passenger. That's what Dexter calls his desire to kill. The dark passenger helps Dexter sense when he is bong watched or when evil is around. But in this book, Dexter loses his dark passenger.
I don't know what happened in this one. Lindsay went all supernatural. It was really annoying. I love these books for Dexter's unique perspective on the world. This perspective was lost in the supernatural and metaphysical story of the dark passenger. Hopefully he drops this theme in the next book.