October “Toby” Daye is a changeling, the daughter of Amandine of the fae and a mortal man. Like her mother, she is gifted in blood magic, able to read what has happened to a person through a mere taste of blood. Half-human, half-fae, outsiders from birth, most changelings are second-class children of Faerie spending their lives fighting for the respect of their immortal relations. Toby is the only changeling who has earned knighthood, and she re-earns that position every day, undertaking assignments for her liege, Sylvester, the Duke of the Shadowed Hills. Now Sylvester has asked her to go to the County of Tamed Lightning — otherwise known as Fremont, CA — to make sure that all is well with his niece, Countess January O’Leary, whom he has not been able to contact.