Welcome to the strange and perilous world of Katherine Colebrook: FBI special agent, Los Angeles... Trackers Division.

Amidst the cases Katherine Colebrook and Reese Johansson are handling, including a pixie invasion, malevolent trolls, and a blood bank robbery, something lurks on the horizon. An enemy that Katherine has had for many years, though she has never known it, and they're about to finally collide head on.

Brought onto a strange case involving a young psychic vampire and her daughter, the two FBI agents are thrust into a dangerous situation that becomes more horrifying with every answered question. As the situation becomes clear and Katherine can finally see her enemy, the case quickly drags in everyone it touches. And once they've reached the point of no return, Katherine knows the only way out is to cut the head off the snake, no matter how much blood she needs to shed in order to swing the blade.