19-year-old twin demon trackers Shaun and Sarah Gallows are used to running into trouble - mostly the kind with fangs - but while Sarah embraces her powers to their fullest extent, trusting her instincts implicitly, Shaun distances himself from his abilities and can do little more than despair at his sister's reckless nature and idly back her up. When they come across 17-year-old Melissa Carling, a demon tracker who's been torturing innocent super-naturals,...