A fantasy novel by Mercedes Lackey, also known as the author of the Heralds of Valdemar and Elemental Masters series. Once upon a time there was a princess named Odette who was kidnaped by the evil sorcerer Eric von Rothbart and subjected to an unusual curse -- she is human only at night under moonlight; by day she is a beautiful white swan. This novel is not about her. This is about the other swan. Perhaps the two swans are not so different after all. Not to be confused with the film Black Swan.