In a bleak, tense sequence in the third act of the novel, Simon tries to assure Maia that despite being Downworlders, they both have their humanity intact. “You’re still human,” he tells her, “in the ways that count […] just like me” (307). Though he puts conviction into his words, he observes that Maia does not quite believe him. He doesn’t blame her for her skepticism, since “he wasn’t sure he believed himself” (307). Simon’s ambivalence about his identity highlights the text’s theme of finding one’s place in a complex, multilayered world. Like Simon and Maia, characters are often shown caught between past and present selves, illusion and reality.

Jace has grown up believing he was the son of Michael Wayland, but now has to find a new identity as Valentine’s child. Clary, who until the age of 15 did not know of magic’s existence, has to cope with the fact that she is not just a Shadowhunter, but the daughter of Valentine. Cassandra Clare uses these fictional dilemmas as a metaphor for the real-world struggle for identity experienced by many teenagers and adults. The first step in finding one’s true identity, the text suggests, is accepting one’s past and present.