Someone has been cutting up demons and removing their body parts, and this doesn't make sense to doctors Eidolon and Shade, the only surgeons in the world who care exclusively for demons. One patient after another has been arriving at the 'demon ER' with missing internal organs, and Eidolon vows to find who has been targeting his race and for what purpose.

To make matters worse for Eidolon's demon-kind, he's just gone and treated a female demon-slayer who heats his blood as no other has. Tayla is a sexy, lustful, demon-slaying warrior who works for The Aegis, a council of humans who have vowed to rid the world of demons. Eidolon knows Tayla's deepest secret: that she is actually half demon herself. She is, in fact, the only being Eidolon has ever seen who has half-demon, half-human blood. And she's the only woman who has ever captivated him so. But is this woman, who is trained to eradicate Eidolon's species, the person responsible for the rash of demon mutilations that are turning his hospital upside down?