When he was younger, it wasn't so bad.

His brother was still there so his dad would focus on him more, making him tougher and more disciplined and better. It was no surprise when he eventually left and joined the army, thinking he was the perfect fit only to end up dead. Isaac wasn't allowed to cry when they found out because his father said it was "his own damn fault he was dead and there was no point in moping over it. He was a terrible son anyway."

So he turned to Isaac instead. Things were different though. When he hit and yelled and threatened Isaac, when he left him in the freezer for hours or refused to feed him, it wasn't out of a sense of misguided love and a need to make Isaac better. Isaac was not his brother, he was hated, not loved. That was the difference. Isaac was always the hated one.

When Isaac found out his dad has been killed he didn't immediately run to Derek, despite what Derek seemed to think. Growing up the way Isaac had left him with a sense of self-preservation and –reliance above anything else, so he took the time to really absorb and react on his own before going to Derek. He was the first to find his dad, the new sense of smell picking up extreme panic, then something cold and foul, then a scent he recognized, something that spoke to him, suddenly disappearing. No one warned Isaac that it was like a vacuum to your senses when someone dies. That vacuum pulled him back out into the alley he had abandoned his bike in, away from the empty warehouse he usually went to hide in whenever he could escape.

He didn't cry when he saw his dad ripped to pieces, only thought of his reprimands when they found out his brother had died. It may have been conditioning but Isaac refused to react for someone who didn't deserve it. Instead he stared and stared and eventually his vision clouded and he felt like he couldn't breathe so he sat down and beat the ground as hard as he could because damn it he shouldn't feel sad. It was fucked up, it was so fucked up, and all that Isaac had learned in school and online had told him it was normal for those abused to still love their abusers but he had never loved his father. Only the ghost of his mother and his brother before he went away. Still, Isaac felt like he was missing something in his chest, like a tick that had suddenly stopped and it was worse than feeling sad would have been.

It was that feeling that forced him to his feet and off, blindly running to where Derek was because if there was something he had learned, it was that he would always rely on someone else.

There was a while where he hated everyone but Derek.

Erica was his new closest friend but she went just too far sometimes and Isaac was never good at being with uncontrollable people and they weren't really friends anyway, it was all circumstance. Same with Boyd, but Boyd was worse because he hated them too. It was clear from the very first moment he was turned that Boyd knew he had made a mistake. The wishes he had, for power and control and a place to belong were never going to be filled by the maelstrom of mistreated teens their "pack" turned into. He tried to stay as far away from them as possible and was clearly terrified of Derek (they all were) so he only reluctantly interacted with Isaac.

It almost made Isaac respect him but then he remembered his words from the ice rink to Scott McCall of all people. "You're right, I don't want to be like them. I want to be like you." Because of course Isaac wasn't good enough, of course the thing that was supposed to make him better than everyone else still left him inferior. One of these days Isaac would tell someone about the voice in his head that sounded just a bit too old to be his own that drove him to smirk and flirt and act like he was finally in control. Maybe he would tell Derek when he wasn't too busy stalking McCall and Stiles (not even a wolf and still more important) because as much as Derek like throwing them around and be a vague piece of shit, he was something for Isaac to anchor onto.

Isaac was always scared. It was hard for people, even were-people, to tell because that's just the way he always smelled and looked. First he was scared of his dad, then he was scared of Derek, and then the hunters, and then Jackson, and then Gerard, and on and on and on. Mostly he was scared of himself.

During the first full moon, the one where Isaac was supposed to be locked up in a cell and then suddenly wasn't, he thought at first he would kill himself.

Derek had explained that he would lose his mind a little, that the wolf instinct would take over and his first and foremost thoughts would be to maim and kill and hunt. Isaac certainly thought that but everyone he knew was already dead. So when the moon rose and his body began to feel like it wanted to rip itself apart, like everything inside of him was twisting and straining, it seemed internalized. Like his body wanted to rip into himself and just take out all of the weight that he carried all the time. To the part of him that was left, Stiles showing up was a great thing because then he didn't have to decide if he would care whether or not he did anything.

Stiles, somehow, smelled important, a little like Derek's (and fuck that, he was human, he didn't have to suffer like Isaac to get into something bigger than himself, to be worth something) (Isaac never apologized for thinking that because if he did then he would have to admit to Stiles that he himself might never have been worth anything), and a lot like Scott's. Mostly he smelled like fear and determination and that drove Isaac to let go and open the cell. It also drove him to turn to Stiles afterwards, ready to attack anything that was stronger than he was.

Honestly, fuck Derek for showing up, Isaac couldn't help but think the next day.

No one ever brought it up but Isaac had an attachment problem. It started at a time that none of them knew about (excluding Stiles, maybe, which was one of the reasons he could never let himself fall into the whirlwind that was his classmate. It would have been too much) and never seemed to leave him. He hopped from person to person, knowing it wasn't healthy and it wasn't safe for his head. Isaac had a fucked up head already though, born and bred, so no one thought to fix it.

(It changed on its own when he watched Allison die in the arms of Scott because he for once realized that he didn't want to be in that position, he just couldn't be that person.)

Isaac was never looking for a brother when he found one. Of all the things that he had found when he had been turned, and ever before that, it had never been a replacement. You can't replace your family; everyone in their fucked up packed taught him that long before they ceased to be. So he didn't look for another brother, never talked about his own, never sought to become anything other than a fighter and a survivor (you didn't have to look too far for that one, his head whispered and this time the voice was older but it was so close to his own that he almost believed it) and someone other than himself.

Of all the fucked up things that Isaac experienced, finding a new brother in Scott was probably the worst of them all because this time, they were both the loved ones. Isaac didn't know how to be anything but hated. Maybe one day he would ask Scott to explain it properly to him.