Kresley Cole 
Sweet Ruin 

An immortal assassin is caught between desire and duty in this sizzling novel from Kresley Coles #1 New York Times bestselling Immortals After Dark series.A foundling raised in a world of humans Growing up, Josephine didnt know who or what she wasjust that she was an outcast with strange powers. Protecting her baby brother became her entire life. The day he was taken away began Jos transition from would-be superheroto enchanting villain. A lethally sensual enforcer on a mission Archer Rune the Baneblood never fails to eliminate his target. In his sights: the oldest living Valkyrie. Yet before he strikes, a vampiric creature pierces him with aching pleasure, stealing his forbidden bloodand jeopardizing his brethrens secrets. A boundless passion that will lead to sweet ruin Could this exquisite female be a spy sent by the very Valkyrie he hunts? When Jo betrays the identity of the one man she will die to protect, she and Rune become locked in a treacherous battle of wills that pits ultimate loyalty against unbridled lust.