Fallen — Michele Hauf

Wanting to be a part of mankind, the angel fell -- losing his halo, the prize that held his earthbound soul. Now Cooper must retrieve it. But wherever the Fallen walk, a Sinistari demon intent on slaying one is not far behind. Cooper knows he must be wary of this demon. But his first encounter with her leaves him curiously hungering for more....

To reclaim her own soul, Pyxion must kill an angel. Not just any angel, but one who's fallen to earth and taken on an irresistible, seductive human form. She never expected that she would feel an attraction for the man she hunted -- or that she might need his help. When faced with a powerful mutual threat, she and Cooper form an alliance. But as the danger heightens, so does the passion...and if they give in, all could be lost.