Lucy has worked as a maid at Pravus Castle — home of the incubi — for a full month now. Then Urian, the castle's ruler, does something unexpected: he announces that he will hand his throne to whichever of his subjects wins Lucy's heart. Three candidates emerge and begin competing for her affection, each in their own way. In a world where the moon never sets and deepest instincts are the only honest currency, the nights grow complicated.