Alec has big plans to mend fences with the Downworlders, while Jace and Clary are summoned by the Seelie Queen.

After a devastating attack at The Institute, everyone is on high alert as the Shadowhunters close in on their hunt for Jonathan; Simon and Maia help a new Downworlder as the Seelie Queen demands an answer from Magnus and Luke.

After centuries of being lied to and treated poorly by The Clave, the Downworlders decide to come together and take matters into their own hands as the hunt for Valentine and Sebastian intensifies. But what starts off as a way to preserve their own, the Downworlders choice to break with the Shadowhunters, could quickly escalate to war.