Aria was raised by the Bone Witch in a hut hidden in the Iron Wood of Markovy. She is content to stay in the forest forever until the day she finds a wounded knight, Sir Roye de Roye, and falls hopelessly in love. Originally from the fabled kingdom of France, Sir Roye had, until quite recently, held the tower of Byeli Zamak for King Demitri's heir Prince Ivan. There he had also guarded the Firebird's Egg, which King Demitri had long ago stolen from the nest atop the Burning Mountain.

Markovy had lain under a curse since the theft of the Egg, which Sir Roye had brought away with him when he fled Byeli Zamak. Charged by the Bone Witch with returning the Egg to the Burning Mountain, Aria and Sir Roye set out across Markovy, pursued by boyars, Tartars and werewolves.

Firebird is an utterly enchanting novel of an eastern Europe that never quite was, a charming blend of fairy tale, myth, fable and history. The story is well-paced, carrying the reader from Markovy to Persia to the Steppes and back again as though riding in one of the Tartar air-ships. It is a coming-of-age story set against a vivid backdrop, in which things aren't always what they seem, where the Killer of Children is doing exactly the opposite, and the god Eros attempts to seduce young virgins, where rocs and firebirds share the sky with airships and a witch's apprentice might save the day.