Immortal Obsession (Vampire Moons #3)

As her Protector, he was bound to oblige her every desire. 

A rogue group of human-hating vampires have overtaken London. But the elite immortals who own much of the city may have found the key to protecting their territory: Madison Chase, an American newscaster investigating a story about missing teenagers. If she can convince someone to help her infiltrate the dangerous faction, she just might stem the bloodletting and find her brother in time…. 

St. John can't escape his dark family legacy. But the instincts that keep him from being fully human also make him the rogues' worst enemy. His desire for the ethereal redhead is immediate, all-consuming and forbidden. And as the investigation escalates, Madison must discover if St. John is her trusted Protector or if she's being seduced by a monster.