Simon Lewis has been a human and a vampire, and now he is becoming a Shadowhunter. The events of City of Heavenly Fire left him stripped of his memories, and Simon isn't sure who he is anymore. So when the Shadowhunter Academy reopens, Simon throws himself into this new world of demon hunting, determined to find himself again. Whomever this new Simon might be. But the Academy is a Shadowhunter institution, which means it has some problems.
In the early 19th century, Tobias Herondale abandoned his fellow Shadowhunters in the heat of battle and left them to die. His life was forfeit, but Tobias never returned, and the Clave claimed his wife's life in exchange for Tobias'. Simon and his fellow students are shocked to learn of this brutality, especially when it is revealed the woman was pregnant. But what if the child survived? Could there be a lost Herondale line out in the world today?