As the last thunderstorm of summer ravages Frances Forest of Fontainebleau, a tiny, lavender faerie seeks shelter inside a hollow oak. It is not long, however, until Fey discovers she is not alone.

Her accidental encounter with an enormous, frightening bat on a solitary journey to the fabled City of Lights has her bargaining for her life by granting him a wish—a wish which sends him from a state of spiritual purity to the messy, complicated realm of humanity, a transition he is ill-equipped to deal with. Taken in by a kind farmer, the transformed being, who calls himself Paolo, learns to cope with the moral complexity of being a young man in contemporary society, while Fey is left to cope with the loss of both her magic and the chance to become handfasted with the noble, chivalrous Guiscard.

Meanwhile, Yasmine, a matchmaker playing a reckless game, has just opened a Pandora's Box that will unleash Paolo's heart and determine Fey's destiny.