The Unhallowed: The Witch Hunter Saga, #5

The King is dead…Long live the King. Nye Saer is four hundred year old vampire. Bad guy, one time leader of the notorious Six who's trying to turn over a new leaf and grow a heart. With all six Roman founders dead and gone, it's up to him to bring order back to the London underworld, but there's one problem. They don't fear him as much as they should. Isobel is the human sister of the newborn founder Alex…and you never want to mess with a founding vampire, no matter how good they claim to be. When she turns up on his doorstep, Nye has to go against everything he is in order to protect her from his enemies. But when strange markings begin to appear all over London, unrest amongst the vampires and his conflicting concern over Isobel will be the least of Nye's problems. He's seen the symbols before and there's only one thing it could mean. The Unhallowed are back...and they're not happy.