As mysterious murders threaten the new peace between Shadowhunters and Downworlders, only Simon, the Daylighter vampire, can help bring both groups together.

Zoey has returned from the Otherworld to her rightful place as High Priestess at the House of Night. Her friends are just glad to have her back, but after losing her human consort, Heath, will Zoey--or her relationship with her super-hot Warrior, Stark--ever be the same?

Still pursuing a cure for her mother's enchantment, Clary uses all her powers and ingenuity to get into Idris, the forbidden country of the secretive Shadowhunters, and to its capital, the City of Glass, where with the help of a newfound friend, Sebastian, she uncovers important truths about her family's past that will not only help save her mother but all those that she holds most dear.