"Haven't I?" Magnus said, and then smiled at him. "Will, you treat me as a human being, a person like yourself; rare is the Shadowhunter who treats a warlock like that. I am not so heartless that I would call in a favor from a brokenhearted boy. One who I think, by the way, will be a very good man someday. So I will tell you this. I will stay here when you go, and I will watch over your Jem for you, and if he wakes, I will tell him where you went, and that it was for him. And I will do what I can to preserve his life: I do not have yin fen, but I do have magic, and perhaps there is something in an old spell book I might find that can help him."