Five years age the Shadowhunters were brought to the brink of oblivion. Emma Carstairs is now a young woman bent on discovering what killed her parents and avenging her losses. Together with her parabatai Julian Blackthorn, she investigates a demonic plot that stretches across Los Angeles. Julian's brother Mark was captured by the faeries five years ago, but has been returned as a bargaining chip. The faeries are desperate to find out who is murdering their kind and they need the Shadowhunters' help to do it.