Clary Fairchild: Jonathan, if you're looking for pity, you're wasting your breath.
Jonathan Morgenstern: I'm not interested in pity. Just understanding. I can't deny the things I've done. But you need to know that's behind me now. I can change. I want to change. Because... whatever good exists inside of you, at least some of that has got to be inside of me too. Somewhere. I intend to prove that to you.
Jonathan Morgenstern (to Clary): You're my sister. I'll do whatever it takes to protect you. You're the only family that I have.
Sebastian Morgenstern: I'm a dead weight, am I? I know when I'm being played.
Valentine Morgenstern: Believe me. Where I need to go, it's too dangerous for you to follow. You, Jonathan Morgenstern, are brilliant... and as cunning and vicious as I have ever hoped for. Listen to me. I will come back for you. I promise.
Sebastian Morgenstern: After ten years of torture in Edom, I learnt to endure pain. In fact, I rather enjoy it.
Sebastian Morgenstern (to Max): That's very, very impressive. Your tracking skills. Isabelle has taught you very well. Perhaps a little too well.
Clary Fray: I understand he has demon blood, I know what he's capable of, but... but he's my brother. God, that's stupid, right?
Sebastian Morgenstern: Oh, no. No! God, it's not stupid at all!
Clary Fray: And if there's any humanity left in him, shouldn't we at least try to save him?
Sebastian Morgenstern: I think so.
Sebastian Morgenstern: Jace is trying to sabotage me. He's trying to... make Clary hate me. But I swear to you, I will end him before I let that happen.
Valentine Morgenstern: Listen. Once we have the mirror, none of this will matter.
Sebastian Morgenstern: I can't have Clary hate me. Not after everything I've been through.
Valentine Morgenstern: Clary doesn't care about you.
Sebastian Morgenstern: Yes, she does.
Valentine Morgenstern: No, Jonathan. She only cares about an English Shadowhunter named Sebastian Verlac. When she realizes the truth about you she will only despise you.
Sebastian Morgenstern: No. You are the one that she despises. I am her brother! She loves me.
Sebastian Morgenstern: You always cared more about the Mortal Instruments than you did your own son.
Valentine Morgenstern: That's not true. Despite everything I've done, I have always... always cared about you.
Sebastian Morgenstern: Do not lie to me. If you truly, truly cared about me, you would have never sent me away.
Valentine Morgenstern: I made a mistake. It was Jace that was...
Sebastian Morgenstern: Shut up!
Valentine Morgenstern: The sword still compels the truth. Jonathan... not a day goes by that I don't think about you. Where I am not haunted by that decision I made. To send you to Edom.
Valentine Morgenstern: Why keep the Verlac boy's visage if you're weaker for it?
Sebastian Morgenstern: I think it rather suits me. Don't you? As does the accent. A bit more... charming than a demonic beast with burnt flesh.
Sebastian Morgenstern (about Edom): I'm afraid it's not a very nice place. The first day I was there, they started burning my skin. Just one layer at a time. They said I was too pretty for their world... Too human. So they made me hideous. But they also taught me how to use my demon blood... how to... draw from its power. See, I may be grotesque in my own skin, but... with it I have power that you could only dream of.