Dear Will,

Today is your 16th birthday, and it is time that you know how very much you are loved, because I fear that I have not done a good enough job at it over the years. The only place I know to start is at the beginning.

William James Herondale. I will never get tired of saying your name, because you are the embodiment of goodness in this world. We hunt demons for a living. We are surrounded by dust and shadows, but you are my ray of light. One of the many I'm blessed with. But you were one of my first. And even as you grow into the brave young man, faithful husband, and doting father that I know you will be, I will still see the wriggling red-faced baby with a fine mop of blonde curls trying to walk so he could follow his daddy to the training room and crying in anger and frustration when his chubby legs couldn't yet hold him.

Your father and I agreed that we'd write each of our children a letter and give it to them at our own discretion (the Angel only knows what your father has planned!), because, Will, there's so much we want to tell you, so much you and your brother and sister deserve to know. Firstly, you kids are the best thing that's ever happened to me. I was thrown into the Shadow World when I was sixteen. I had no experience, no one to go to, and no idea what was going on. Your dad saved me. In so many ways, Will, that I hope you understand someday. I know that he's a difficult man to get close to. I'm not trying to make excuses for the way he is, but I want you to understand. You know how he is. He covers serious situations with sarcasm and humor. He still has a hard time showing his feelings, but that doesn't mean he doesn't have them. Shadowhunters are, by nature, the most reserved, emotionally distant people I have ever met. Upon first glance. But when you get to know them, they're just as susceptible to pain and love and passion as anyone else. And your father is no exception. He may not show it, but he loves you so much. So this is why I'm writing you this, to tell you the real story about how you changed our lives.

Your father and I got married in July of 2011. I had just turned twenty. Your Grandmother Jocelyn wasn't too happy about it. She was afraid for us, afraid that we would make the same mistakes she did. It's taken me a long time to convince her that your father's not Valentine, even if he was raised by him. That was early July. By the end of the month, we had more news for her: we were pregnant. And, oh, was she terrified! But she wasn't nearly as terrified as your father! I've never seen him so anxious as he was the day I told him we were having a baby. Jace Herondale, who laughs in the face of Greater Demons and who walks through Hell like it's a Sunday afternoon stroll, was scared out of his mind. He would never tell you this, but I don't think he thought it would actually happen, at the very least not so soon. Your dad has always been a rebel: wild and reckless and fierce. And he did all the things that wild and reckless and fierce teenage boys do (and I had done many of them with him before we were married), and he had never suffered any consequences. I think he was beginning to think he was invincible to them, so when his new, young wife got pregnant immediately after they were married, I think it was the universe getting a minute amount of revenge. If I had known what the next nine months were going to be like, I might have waited to tell him about you. Then again, I probably wouldn't have been able to. I can't keep many secrets from your father for long.

We were living in our house, the Herondale family mansion, here in Idris at the time, but it wasn't the house you know. It was rather disheveled after being empty for so many years, and your father had promised that he and your Uncle Alec and Uncle Simon and Grandpa Luke and some of the rest of the New York pack would fix it up soon after we moved in. Well, needless to say, they started working a lot sooner than your dad had planned. In only a few months, the whole house looked brand new. Your dad was so proud, especially of your nursery. By then we knew that we were having a boy, and I think that thrilled (and scared) him even more. He loves Charlotte, you know, but I think that the prospect of a son, someone who would carry on the family name, was more important to him than he would ever let on. That's why the Angel sent us you. I also know that it terrified him. A son meant a boy, possibly a boy just like him, and then everything he'd ever done, every rule he had ever bent (or blatantly broken) and all the danger he had put himself in came crashing down on him in that moment. And he hoped that you wouldn't do the same. But I have experience with the Herondale bloodline: you are headstrong; you are bound by honor, and you are reckless. You do whatever it takes to do whatever you think needs to be done. You are loose cannons that run straight at the source of the threat. But you do it for all the right reasons. You do it for love and justice and to protect those you love and those who cannot protect themselves, and I cannot fault your blood for that. The Herondales know, as well as anyone, that there are some things worth dying for. And you have certainly proven yourself to be a true Herondale, Will, from the wit in your head to your long pianist fingers to the core of your soul.

I know it's cliché, but I loved you from the moment I knew you were inside of me. I know it's really cliché, but I loved you even more the moment I held you. You were your father in miniature: soft golden curls so fine that you could barely see them and light brown eyes that gleamed gold in the light. You were my son, but you were an answer to your father's prayers. I know he had never loved anyone or anything so instantaneously as he loved you, not even me. You have to understand, Will; he was only twenty-one. I was only twenty. The fact that you were ours, that we were responsible not only for bringing another life into this world but also for caring for it and raising it and teaching it the ways of Shadowhunting, was a wonderful and terrifying thing for two people who were barely more than children. Yet, somehow, our tender age and inexperience didn't affect the overwhelming love we had for you. As custom dictates, a Silent Brother and Iron Sister were present at your birth and anointed you with the protection of the Angel so that your soul would be strong and your body unsusceptible to evil spirits. For good measure, your father and I also brought in the warlocks Magnus Bane and Tessa Gray. Now, you may call us superstitious, but Magnus and Tessa were dear friends of ours (and still are, seeing as Magnus is married to your Uncle Alec, and you've referred to him as 'Uncle Magnus' (much to his disdain and everyone else's amusement, might I add) since you could talk), and we believed that surrounding our child with as much love as possible early in his life was crucial to his development. I think it also helped your father, who nearly passed out from nerves. Regardless, everyone was there, Will, and I do mean everyone. Grandma Jocelyn and Grandpa Luke, Uncle Simon and Aunt Izzy, Uncle Alec and Uncle Magnus (several years before they got married), and Bat and Maia (long before Jordan and Lily and Lucas and Juliette were born). Even Grandma Jocelyn and Uncle Magnus' friend Catarina Loss stopped by to see you. From the beginning, Will, there were so many people who loved you, and that number has only grown since, but no one has ever loved you more than your father. I love you more than I have ever loved anything, but he loves you with ever fiber of his being; every cell in his body is programmed to love you so strongly and has been since before you were even born. You filled in another hole in his heart. And I think that's partly why he was so scared. He had never felt such a strong rush of emotions before. He broke down the first time he held you and cried more than I'd ever seen him cry. He doesn't cry, your father, at least not so that other people can see. That's how I knew he loved you. And, despite what I'm sure you sometimes think, he hasn't ever stopped loving you. And neither have I.

I wish you could stay my little boy forever But Shadowhunters grow up fast, and those days are long gone. You might be 16 now—and the Angel only knows what stories you've heard about the things your father and I got into at 16—but go easy on me, Will. Try not to grow up faster than you have to.

All my love,

Mom