No matter what your normal preferences are for books, this is one that'll capture your interest.
Even if you don't like feeling queasy, you'll be enthralled as the main character, John Wayne Cleaver, helps with the human embalming. Even if you don't like mysteries, you'll be gripping the pages as John follows the trail of a supernatural killer. Even if you don't like dark fantasy, you'll find yourself pondering the soul of a fanged, razor-clawed demon, who at times is more human than his prey. And even if you don't like thrillers, you'll keep holding on to the character of John, who offers sincere vulnerability while managing to terrify you with what he could become.
This book defies many genre boundaries, which leads to a rather generic-sounding-but-completely-accurate recommendation of: "If you're interested in what's fascinating, you'll love this."