"She wasn't even sure why it was that she liked it— the clothes, the music made it like a dream, someone else's life, not her boring real life at all."
The line found in the first chapter foreshadows one of the main themes in the book: the search for one’s true identity. Even if Clary tries to convince herself that the alien feeling is just a desire to get out of her boring life, she unconsciously knows that the life she has is a lie. Her attraction to the Shadow world and their way of life becomes a conscious thing even if she is not aware of the hidden. She is attracted to the style and life that they have but doesn’t recognize that she is also meant for that life. For Clary, this represents the beginning of her struggle concerning her place and her true identity.
"This is Hugo," the man said, touching the bird on his shoulder. "Hugo is a raven, and, as such, he knows many things. I, meanwhile, am Hodge Starkweather, a professor of history, and, as such, I do not know nearly enough."
The raven is a common symbol used in literature. Most of the time, a raven refers to one’s intelligence and cunning nature. Ravens are also considered to be bad omens and are linked to death. It can be said that when Hodge talks about the raven knowing many things, he is talking about Valentine, the master of the raven. Just like Hugo, Valentine is an intelligent man who pulls the strings from the shadows and knows more than others think. When Hodge talks about knowing too little he also talks about the others not realizing the imminent danger and that they lack the knowledge necessary to observe Valentine’s presence.
"I hereby render unconditional obedience to the Circle and its principles…. I will be ready to risk my life at any time for the Circle, in order to preserve the purity of the bloodlines of Idris, and for the mortal world with whose safety we are charged."
The loyalty oath represents the Circle’s view regarding those they consider pure or linked with protecting. The oath is the starting point of Valentine's hatred of Downworlders and the motive for his actions. He considered the Shadowhunter race as a superior one, a blood that is pure above all and must be protected, and the human race that needs to be saved but is not necessarily considered superior. Valentine is willing to sacrifice human children if that means creating more Shadowhunters and that points to the belief that humans are disposable when the idea of creating Shadowhunters possible.
"Her stomach dropped out from under her as the silver river spun away and the spires of the bridge slid under her feet, but this time Clary kept her eyes open, so that she could see it all."
Clary’s acceptance of her new life and desire to discover a world hidden from her is underlined in the book's last line. In the first chapters, Clary is reluctant to accept that her life is not what she thinks it is and that it may have been built on lies. In the beginning, she also struggles with her identity, her place in the world, and how she interacts with those close to her. The end of the book symbolizes her desire to see everything, her willingness to learn as much as possible about the Shadow World, and her acceptance of her new identity.
“The boy never cried again, and he never forgot what he'd learned: that to love is to destroy, and that to be loved is to be the one destroyed.”
The bedtime story that Jace shares with Clary is a story of his past when he lived in the manor house in Idris with his father. Jace decides to trust Clary and shares an anecdote of his past with her. It shows us the reason for Jace's distaste for love, that he considers loving a weakness, which slowly corrupts one's strength from the inside. Being a Shadowhunter who was taught to value strength, he believes that being inflexible is a good thing.
