For as long as Isabelle Lightwood could remember, her best friend had always been her big brother.

She used to listen to others complain about their siblings, truly annoyed or angered by the other. Izzy had never participated in such conversations. There was no reason to. Alec wasn't just her brother, someone to tolerate and love because he was family. He was the most important thing in the world to her.

As the memory demon that Magnus had summoned with their help had shown, Alec was the person that Izzy loved most in this world. It had been that way forever.

She remembered the first time she had a crush on a boy. Her too young heart had been broken when the boy had rejected her immediately, acting as if the thought of her liking him was revolting. Not even old enough to have her first angelic rune, Izzy had learned what it meant to be judged on sight and found unwanting.

Alec had been the one to seek her out upon hearing what had happened. He was the only one to take the event seriously, to understand just how badly she had hurt because of that boy (someone she couldn't even remember the name of now).

"He's just intimidated by the fact that you're a better fighter than him, and that you're three times more brilliant." Alec said when he found her in her room eating cake that she had stolen from the kitchen.

Young and naive, Izzy had responded, "I don't have to be." All she had really wanted at that time was to be liked back.

He had gotten mad at that. "Don't you ever change for anybody. If he can't accept how amazing you are, then he doesn't deserve you."

There was also the time when she was to chose her first weapon. Their mother had practically scoffed at the idea of Izzy wanting to use the whip. "You've hardly proven yourself disciplined enough for such a weapon." Even their father, whom she had adored at that time, had said it was too dangerous for her.

It was only Alec who had shooed away6 their concerns. "If that's what calls out to you, then that's that," he commented as if it were that simply while they spared in the otherwise empty training room. "Trust your instincts, and don't let anyone else tell you any different." He knocked her down, having never believed in the concept of going easy on her, though he was certainly kinder about it than their mother. "For what it's worth, I think you'll be great it. Like you are in everything else."

Then when she had reached adolescents, growing into herself and feeling more confident and powerful - and dressing in a manner that represented that fact - it was only Alec that had understood why she began to dress the way she did.

She had heard others whisper how she only wanted her parents' attention, crying out for them to notice her. It wasn't. She was already her father's favorite, and she had long since accepted the fact that she would never be good enough in her mother's eyes. Nor was it to use her beauty as a weapon, as many of the Shadowhunter boys that she had beaten in the training room sneered as they limped away. Izzy knew for a fact that she was dangerous enough without it.

No. She dressed the way she did because she enjoyed looking sexy, and because it was fun. Alec may not have always approved of the way her attire caught the skeezy gaze of men, but he understood her and he accepted her the way she was.

That was probably why he had been the first one to notice her change of wardrobe, and why he had been worried about the change. It was because he knew that by changing her style, she was saying that she was willing to change herself...to mold herself into the image that someone else wanted (specifically their mother).

He taken her aside and spoke gently. "You don't have to change who you are. And you don't have to hide who you want to be."

That was the way their relationship worked; with Izzy confiding her thoughts to Alec, or Alec just automatically knowing that something was wrong and putting it upon himself to fix it.

Of course, as much as Izzy appreciated his words of sentiment, the older they got, the more annoyed she became. For as sincere as his words were to her, she later recognized how hypocritical they were, and how much sadness was laced into them.

It was times like those, when Alec was comforting her but she was allowed to comfort him back, to tell him how amazing he was (not that mask he put on, but the truth him), that as much as he was her best friend, somewhere along the line she had stopped being his.

Maybe years ago he had considered her his best friend. Unlike other boys his age, he had never been irritated by the fact that he had a little sister tailing after him, waiting to tag along wherever he went. He was always glad to play whatever game she suggested, or to spar. Sometimes they'd even fall asleep in each other's room, having stayed up late into the night talking and laughing.

Back then, she had felt that she was as much his confidant as she was his. Like the time Alec had confessed his doubt in being Jace's parabatai because he had begun to feel unplantonic feelings towards the blonde. She had come to the conclusion with only the slightest bit of surprise, and had accepted him just as he had always accepted her. And he had trusted her enough to go through the parabatai ceremony.

There were even rare moment in their teenage years when Alec would talk to her about him being gay - though he never actually said the word -, trusting only her to keep his secret.

Somewhere along the way, however, all that had changed. Izzy wasn't sure why it had happened (she was intent on blaming her parents), but suddenly Alec didn't share things with her like he once had. Thinking back, she supposed the change had been gradual, but all she knew was that overtime Alec had drawn inside of himself, going so far as to even block Izzy out.

He was still always there for Izzy when she needed him of course, but he no longer sought her out for himself, despite the fact that she knew he needed someone. Someone who would also accept Alec for who he was, and would remind him that he was a wonderful person who deserved to be loved for himself. Not this pretense that he had set up to appease their parents and the Clave.

That was what he needed. Someone worthy enough to see beyond the mask to the real him.

And Izzy would make sure that he found that person. Or, really (he had already found that person), she would do everything in her power to make sure that he held onto that person.

It was least she could do for her best friend.