A week after the close of City of Ashes, Clary prepares for a trip to Alicante, the Shadowhunter city in the country of Idris, where she hopes to find a warlock who can help wake her mother from her enchanted sleep. While there, she plans to meet with the Clave—the Shadowhunter governing body. Believing her plan to be dangerous, Jace tries to prevent Clary from going. In addition, Simon has been acting strange since he and Clary broke up a week ago. As she packs, Clary confesses to Luke that she wishes things could go back to normal, to which Luke replies, “Normal isn’t all it’s cracked up to be” (12)—a loaded statement applicable to the whole of Clare’s expansive Shadowhunter universe.

The Shadowhunters are supposed to take a portal to Idris that night, but Jace calls Simon to the Institute as the Lightwood family is preparing to leave and asks Simon to lie, telling the group that Clary changed her mind about going with them. In the previous book, Clary amplified a rune that destroyed Valentine’s ship, and Jace fears that the Clave will want to weaponize her power, putting her in danger.