The epic conclusion to the story that began with Mary of the Aether and continued with Mary of Shadows and Mary of Starlight. One enemy remains, a creature more devious, cunning and cruel than any Devourer. Mary the Lightbearer will face this enemy in a last world-shattering battle that will change the fate of universes. But it is a battle like no other against an evil force greater than anything Mary has ever known. The truth about many things will be revealed, and no one will ever be the same.