Isaac and Matt weren't close friends, but they were friends all the same. Isaac had an ingrained hesitance, born from the fear of his father, that made it difficult to get close. But Matt was warm and friendly and had drawn Isaac into as close a friendship as he could manage. They'd bonded over their mutual love for comic books.
Isaac didn't have very many, his father didn't think much of them, but he did have a first edition Batman comic stashed away where neither his father or brother would see it. Matt loved Batman; it was his favorite. He offered to make a trade – Isaac's first edition Batman for Matt's first edition Spiderman. Isaac didn't like Spiderman as much, but it would make Matt happy, and they were friends.
Matt came by after school, Spiderman clutched tightly to his chest in its protective cover. They went into Isaac's room to hang out and make the trade. They slid the two comics from their sleeves and flipped through the pages reverently, enjoying their own comic books for what would alternately be the last and first time. Afterward they talked for hours about all the different heroes, who had the best powers, which one would win in a fight, best villain.
Isaac's heart nearly stopped when he heard the scratching of the key in the door. He hadn't realized how late it had gotten, hadn't meant for Matt to still be there when his father and brother got home. He listened, frozen in horror, Matt looking at him in confusion. Then he heard his dad, happy and authoritative, inviting people in, directing them through the living room to the pool out back. Isaac breathed a sigh of relief.
He knew that if his dad was happy the swim team must have won, that he must have invited them back to the house to celebrate. There would be a small party, his dad and brother would be distracted. He decided to wait until things got started before ushering Matt out.
Isaac almost had him to the door when Matt paused. There was music filtering in from the back; Matt moved toward it. Isaac grabbed for his wrist but wasn't able to catch him.
"Matt don't," he whined helplessly. Matt ignored him, heading closer to the back doors, closer to the music and the swim team and Isaac's father. Isaac trailed nervously several feet behind him. There was an elated scream from a girl and a splash followed by several more. Then Matt was standing idly just outside. Isaac watched in horror as his brother, Camden, scooped Matt up. He carried him, flailing and frantic, to the edge of the pool.
"Come join the party!" Camden shouted mockingly before tossing Matt into the pool. Matt splashed into the water and flailed desperately. His head broke the surface with a gasp.
"I can't swim! I can't…" Matt cried before slipping under again. Camden was laughing along with a few others. Nobody really seemed to notice what was happening. Isaac's whole body was shaking, afraid to go out there, afraid to let Matt drown. The seconds ticked by like hours in his head. There was still no sign of Matt emerging from the pool and no one was going to save him. Matt was dying. He was drowning.
"He's drowning!" Isaac screamed. His feet started moving on their own, leading him to his father. He tugged at the black sleeve of his sweater. "He's drowning! He's dying! You have to save him, dad. Matt can't swim," Isaac pleaded. His father looked at him, his eyes full of anger and disgust. He shook Isaac off, sending him sprawling to the ground at someone's feet. But his father was moving too, jumping into the pool and reaching Matt in two broad strokes. He pulled him out, tossing him beside the pool before dragging himself up beside him.
Isaac watched in terror as Matt lay still, not breathing. His father started administering CPR. On the second set of chest compressions Matt sputtered, coughed, and took a breath. Isaac breathed with him.
"You tell no one!" Isaac's father shouted angrily. The mood sobered instantly and everyone was silent. "This, this is your fault! You don't know how to swim? What little bastard doesn't know how to swim?" Isaac closed his eyes and tried to push the fear and the guilt away. "You say nothing! You tell no one! No one!" His dad stood up sharply, whirling on the guests. "Get out! Everyone go home!" They obeyed wordlessly. Isaac's father reached down and grabbed Matt's shirt roughly, yanking him to his feet. He dragged him out to the car, drove him home. When he came back he yelled at Camden but punished Isaac.
When Isaac saw Matt at school on Monday there was a hollowness to him and he looked tired. He shot Isaac furtive glances all day. They didn't speak. Isaac wanted to talk to Matt, make sure he was okay, but he couldn't, didn't know how. Matt had been exposed to his father's fury, had glimpsed a part of Isaac's life that he was trying to keep hidden, trying to erase and pretend didn't happen. And Matt had almost died; and it was Isaac's fault. If Isaac had paid more attention, if he'd stopped Matt from going out there, if he hadn't let him get so close in the first place… There was nothing to say.
Afterwards Isaac was hyper-aware of Matt. They weren't friends anymore, couldn't be, but Isaac noticed him, watched him. He watched Matt hang around the fringes of friendships, social enough for people to like him, reserved enough to never get close. He watched him shake when he got too close to water. He watched his angry, disappointed expression when the people who had nearly killed him barely noticed he was still alive. Worst of all, he watched Matt grow cold. It didn't take long before he barely reminded Isaac of the boy he'd known, and it ached inside him.
In high school they both joined the lacrosse team. Neither of them made first line. They changed side by side in the locker room and never looked at each other. They sat a few feet apart on the bench and didn't say a word. Matt took pictures and was friendly with the rest of the team. It made Isaac feel more alone.
When Derek offered Isaac the bite he accepted it gladly. The threat of hunters seemed no more terrifying to him as a werewolf than the threat of his father was to him as a human. The promise of pack, of a family that would protect and care for him, of a place to belong, was overwhelming. And he would be strong. As a werewolf, Isaac would be strong enough to protect himself and others. Strong enough to keep Matt from drowning.
Isaac's father died and Isaac became a fugitive. Other people died too. There was some kind of monster terrorizing Beacon Hills, something different than a werewolf. Derek called it a kanima. They tested its venom on Jackson and he was paralyzed. He cleared things up with the Sheriff and Isaac returned to school. Derek sent Isaac and Erica to test Lydia; she was unfazed. They followed her scent into the library.
Being a werewolf made Isaac feel powerful and he was relishing it, basking in the chance to protect everyone, to be a hero. His face fell as he opened the door. Lydia's smell was weak here but Matt's was strong. He was sitting with Danny. Jackson had been with them, had probably left with Lydia. Matt was too close. Isaac grabbed him roughly, pulled him out of the chair, demanded he tell them where Lydia had gone. Isaac wondered if he reminded Matt of his father as much as Isaac reminded himself. He told himself that was good; if Matt was afraid he would stay away, he would be safe.
Matt wasn't safe. He was in the library again, in detention with Scott's pack and Erica, when the kanima attacked. Erica had a seizure and Matt got a concussion. Isaac felt weak; he hadn't been there to protect them. Matt could have died, again, and it was still Isaac's fault.
After that there was no question that Jackson was the kanima. They made a plan to catch him at a rave. Isaac tensed when he caught Matt's scent in the crowd. It didn't matter, they would catch Jackson and Matt would be safe. He felt confident when Scott pushed the plunger into his hands, he could be the hero.
"I don't want you to get hurt," Scott told him. It made the guilt roil in his stomach. Isaac and Erica cornered Jackson on the dance floor, caged him in with their bodies. He sunk his claws in just as Isaac was about to inject him, sent the plunger skittering away.
Isaac had failed. Jackson was here to kill someone and the pack and Matt were in danger. It felt too familiar, the music pounding in his head, everyone oblivious to the danger; Kara was even there, mixing the music without a care in the world. His resolve hardened and he grabbed the injection, stalking quick and deliberate to press the needle into his neck. It was only temporary. The kanima got away.
Isaac was still struggling with the full moon when everything happened. It was only after that he found out about Matt. Matt had been controlling the kanima; taking revenge for what had happened that night. Was Isaac somewhere on the list? It didn't matter. Matt had drowned. Matt had been murdered. It wasn't Derek or Scott, so it had to be the hunters. It left a bitter taste in Isaac's mouth.
In the end that's why he stayed. Part of him wanted to run with Boyd and Erica, to remain a pack even without Derek. But the hunters had killed Matt. They had killed him in the cruelest way imaginable. Isaac couldn't save Matt, but he could finish his revenge. He could be his hero. So he stayed and he fought. And they won. It was a hollow victory.
After Gerard was dead and Jackson was a proper werewolf, Isaac went to the cemetery. There hadn't been much interest in Matt's funeral. Only his parents had gone, and even they had gone with an air of hesitation. They hadn't really known their son, no one had. Isaac scraped up a shallow hole in front of the gravestone. He set two first edition comics in the hole and covered them in dirt. It was time to bury his regrets. It was time to say goodbye.
"I'm sorry I just watched you drown."