Ghost of A Chance (Vampire Dead-tective #4) - Vampire Dead-tective, #4

Liz and Vince follow the trail of clues left by Tim in their search to solve the reason for his murder. The trail turns cold as death, but that's a good thing for them when the person they want to speak with is a restless spirit with a firm demand: find her body or she won't give them the clue they're looking for. Their new case leads them from a zombie encampment to the bowels of the supernatural fighting world and back, all the while being harassed by devils and stalked by the undead.
It's a usual night for the pair as they survive one request after another in a wild night of mysterious mayhem and paranormal chaos.