As a fae-vampire hybrid, scorned by all, Holden's life has never been easy. The one bright spot is his job testing blood at supernatural crime scenes. It's routine work, until the day he finds a victim he can't read. When one murder becomes two, and then three, it's clear there's a serial killer on the loose-one with a penchant for collecting hearts. Finding the bad guy could cement Holden's career, but he's drawing a blank. And it doesn't help that the expert his boss calls in to assist him is the man Holden's been crushing on for years. With lives hanging in the balance, Holden and Val must solve the case before the killer strikes again. But will they come out with their hearts still intact?