Once upon a time-oh, many, many years ago as time is calculated by men-but which was only Yesterday in the Celestial Calendar of Heaven-there was, in Paradise, a most miserable, thoroughly unhappy, and utterly dejected cherub who was known throught Heaven as The Littlest Angel.

Haven Terra and her friends team up with aspiring angels to combat an enclave of shape-shifting devils, an effort that is complicated by Haven's infatuation with repentant devil Lucian, who needs her help to escape the underworld.