The war between angels and demons has gone on for far too long.
The story follows Eva, a young woman who discovers she's the last "Keeper" tasked with finding the powerful Salador ring. She's aided by Azrael, an angel cast out of the celestial realm, and Scythe, a vampire with a mysterious past. Together, they battle demons and angels to prevent the ring from falling into the wrong hands. Along the way, Eva develops feelings for Scythe and finds out her own hidden powers. When Lucifer steals the ring from her, Eva must stop him and save both the human and celestial realms. In the end, Scythe saves Eva's life by turning her into a vampire, and Azrael returns to the celestial realm.