Hey, so... this is my first story in a while. Who knows if I'll finish my other two? I felt like writing this, so I did. (Badly.) So here's a short, Izzy-centric fic.
First it is just the two of them. Izzy and Alec Lightwood, children left to roam the long and dusty halls of the New York Institute alone. At first, he plays with her, holds her hand and puts her down for a nap, tells her the stories of their world. Their parents travel constantly and fight monsters daily, never the ones to spend time with their children. So Izzy clings to Alec and Alec puts up with it, because Isabelle is his sister and he doesn't have anyone else either. Then Alec draws away. She's younger, and she's pesky, and she questions everything, and it was all so terribly annoying (his words) that he just doesn't want to spend time with her anymore.
And so the corridors they explored together were the ones she ran up and down, shouting:
"Alec! Alec!" She would yell his name out loud enough for her screams to rip through the Institute and reach her brother, wherever he was within it.
"What? Izzy, what's wrong?" He would cry, racing to her. They were both too young for any weapons, but they were Shadowhunters, and their hands were enough to fight anything deemed as harmful within the Institute's boundaries.
"I was lonely." Izzy would pout, her voice hoarse from screaming as loud as she was. She would throw her arms around her older brother's torso and look at him with big eyes. Alec would, in turn, snarl.
"What's wrong with you?" He would ask on these occasions, peeling her arms off of his body. "Haven't you ever heard the tale of the boy who cried Ravener? Cut it out, or next time I won't come running." Alec would then turn on his heel and stalk back to his bedroom. This repeated, many, many times, much to Alec's dismay.
He lied. He always came and searched for Izzy when she called. Alec, even as brooding as he was at such a young age, was too scared of losing anyone to not run by her side any time she called for him.
Max is born, and she's ecstatic. Someone younger, someone she can boss around, someone who wants another to spend time with. She mothers him more than their own mother does, bringing him everywhere with her and feeding him and rocking him to sleep. She turns her loneliness into a fondness for her little brother, and she becomes so shockingly close with him she figures she will never need anyone else again.
But still, he is seven years her junior, and he isn't great company when he screams and cries enough to make her do the same.
She's ten years old when Jace Wayland comes to stay, and she is overjoyed. Finally, someone to talk to, someone to show around and train with. She hears from her mother that Jace had seen his own father die, and she expects him to be weak. She imagines him easy to speak to and them becoming fast friends. However, he is as independent and strong as she is in her early years, and definitely isn't too excited at the prospect of a young girl who keeps insisting on being included and who possesses a stubbornness to match his own hanging about all of the time. Much to Izzy's disappointment, Alec chooses this time to peek out of his bedroom and make a new friend, ripping Jace away from her before they could even have a conversation, and leaving her left out once again.
The two become parabatai and Izzy aches for one. It physically hurts how alone she is, the gnawing in her stomach she feels whenever she sees Jace and Alec applying each other's runes or fighting side by side. Alone, her heart screams. Shut up, her brain shouts back, choosing to be strong rather than spill a single tear over something so foolish.
The isolation helps her grow, of course. She toughens, could probably stitch herself back together with no runes to help her if needed. She becomes more perceptive, because she has no one to talk to, and she notices things no one else can. She notices the feelings Alec harbors for his parabatai, as she notices the reckless glint in Jace's eyes that she solemnly notes would probably get him killed.
She focuses on training. Sometimes she does it all day. She wants to be as good as Jace, but practicing twice as hard for twice as long isn't enough to become as gifted and effortless as he is on hunts.
Eventually, Alec and Jace come around, namely when they start hunting in a group. They gain a newfound respect for her when they see her natural talent for shadowhunting, and though she becomes closer to each of them, she is still their little sister.
She clings to the boys she dates as tightly as she had clung to her brother as a child, afraid of being alone but always conscious of her actions, never coming across as vulnerable. Max no longer needs a mother figure and she no longer wants to be one. Besides, she spends all her time hunting and Max is often dragged along with their parents on official Clave business. So she dates those boys and throws them away, because she can't stand to be alone but hasn't believed in love since learning of her father's affair.
Clary comes to the Institute, and though she doesn't show it, Isabelle is more hopeful than she has been in her entire life. A new Shadowhunter, a girl, someone she could train with, talk to, and by the Angel, it was a girl.
But Clary already has a best friend. She becomes very friendly with Isabelle, but nothing more. Isabelle had once naively wished they would become inseparable, and later parabatai, but no such luck. A girl with a vampire for a best friend would one day manage a way for him to be her parabatai, and Izzy couldn't even find one after years of searching.
Max dies and it hits her the hardest. So damn hard, it feels like her bones are breaking and like she wants to die, too. She screams and cries and clutches Alec in the days leading up to the funeral, and there she weeps a few tears and decides to weep no more. But she feels so sick. Sick from seeing her brother's casket, sick from seeing her mother, someone who barely spent time with him, weeping as if she was the one who taught him, cuddled him, saved him from his nightmares. Sick because it was Max. Her little brother. The person she probably had been the closest to. Dead.
Alec starts dating Magnus and she makes an effort to talk to the warlock because he, out of anyone, would understand solitude. They never become as close as she wants. As she needs.
Isabelle settles with the fact that the universe does not want her to have a best friend.
She falls in love with Simon, and Simon has Clary, always someone else to turn to.
And Izzy does not have anyone like that. But she is strong. And she tells herself she doesn't need one, but that's a lie that she's told herself before and will tell herself again.
She yearns for someone to notice. For someone in their large friend group to see that when everyone else is in conversation, she's the only one who stares blankly at them all, left out for what feels like, to her, the millionth time. No one does, and she keeps these emotions and thoughts bottled up, because she doesn't want to be pitied and she doesn't want anyone to spend time with her without truly wanting to.
Isabelle Lightwood is alone, dreadfully, hopelessly so, and no one seems to care.