Valley of Lights — Stephen Gallagher

Supernatural fusion of horror and police procedural set in Phoenix, Arizona. When Police Sergeant Alex Volchak discovers the true nature of a predator that has survived among us unnoticed for generations, he places himself and those around him in mortal danger. It's older than the desert, a thing without a name, but as vicious, jealous and self-preserving a creature as ever walked the earth. And it hides in plain sight.