A/N: There needs to be more sibling fics. Because sibling fics rock.

Disclaimer: I don't own anything you see before you. I'm just sitting here wishing I did.

Summary: Katara thinks about Sokka and how everything changed when their mother died after over-hearing his conversation with Toph. Set during 'The Runaway'.

Might Break You
By: Reggie

Katara couldn't say for sure whether or not Sokka had meant for her to hear those things. It was Sokka, and he almost always had multiple reasons for doing anything he did, so there was a fairly good chance he'd wanted her to know.

A part of her thought that he really hadn't known she was down there and he never meant to tell her about how much he hurt because he couldn't remember her.

That stung, in its own way. He would never tell her, even hint, that he might miss her as much as she did.

No, that wasn't right. Of course Sokka missed her. He just…wouldn't talk about it. He never had.

Katara sighed, tilting her head back and letting her dark hair float about her in the water. Everything had changed that day. Not just because she'd been needed more than ever, and not just because she no longer had her mother to teach her things, to read her bed time stories, and kiss them both good night.

"When our mom died…that was the hardest time of my life. Our family was a mess."

He'd said it like it was that simple, but even just remembering made it hard for her to breath and her stomach start to twist uneasily.

He wouldn't tell Toph what had happened. Of course he wouldn't. No one knew what had happened but the three of them, and try as she might Katara could not keep the memories at bay. They were too much like the ocean. She could control pieces, but to control the whole was beyond her.

She remembered Sokka as he'd been as a little boy, when the war was nothing but a far off story for them. How he'd laughed, always causing mischief that would bring the whole village to their doorstep to complain to their parents. He was menace, but somehow everyone loved him anyway. His smile had been infectious and everything he felt had been so real.

How she had admired him! She could remember following Sokka everywhere, wanting to play with him and his friends when they built snow forts and played war. And he'd always let her, even joined her in being Fire Nation when the other boys made her so that she wouldn't have to fight alone. She had adored him, just as everyone seemed to.

Then, the ash had started to fall. Sokka was the one that noticed it first, when they had been waiting for the men to return from fishing by playing on the shore. He'd seen the black flakes falling from the sky, and gone to ask their mother about it. Only Gran-Gran was old enough to remember what it was, but by the time anyone thought to ask her there was almost no time left to prepare.

Katara closed her eyes, desperately wishing her phantoms away. But the screams of the women and children, defenseless with the men gone, would not be banished so easily. She could almost feel the heat on her skin again, and her mother grabbing her hand, desperately dragging them both to the ice caves that lay beyond the village.

She has pushed them inside and held them close, and though their mother had tried to shield them they could still see the flames and hear the screaming of those who could not get away.

The young Waterbender could not say for sure what it was that had set her brother off, but Sokka had always been loyal and loved his village deeply. One moment, he was crouching next to her in terror, and the next he'd let out a yell of fury and was taking off across the snow—the small knife their father had given him clutched in his hands.

Katara could remember her mother's yell of fright, trying to call him back. She'd been pushed further back in the cave, and told to stay there no matter what happened or what she heard.

She had done as she was told, covering her ears and closing her eyes as tight as she could while she waited for her family to return. They hadn't come back, and the sun was going down before she dared to peek out.

There were people wandering around below, and the air was populated with cries of dismay and grief. Her home was gone, nothing but piles of ash and smashed snow. She'd run, the cold air stinging her chest, calling desperately for her family.

She had found her mother and father first. Hakoda was kneeling in the snow, cradling his wife's limp body to his chest as he sobbed.

Katara, frightened as was, ran toward him. He'd scooped her up and held her so tight she almost couldn't breathe, kissing her hair and showering her with tears.

She was told later that the men had shown up during the attack and had managed to force the Fire Nation into a retreat, but not before the Water Tribe suffered heavy losses. A couple of children three or four years younger than Katara had survived, as well as a handful a few years older, but that was all. All of her friends, Sokka's friends, and many of the women had been ruthlessly killed.

She had tried to wake her mother, refusing to believe she could really be gone, but her father had stopped her and held her close while she'd cried. Hakoda had asked her where Sokka was, and she had told him all about how he'd run. She had just finished her tale when Gran-Gran had come up, Sokka stumbling along behind her.

Of all the things that happened that day, including her mother's limp form on the red stained snow, Sokka was the one she remembered the clearest. His eyes were far away, as though they couldn't really focus on what was in front of him. His clothes were torn and he was covered head to foot in blood.

At Katara's gasp, Gran-Gran had assured her that he was fine, and moved to hold her tight.

What happened next was something Katara would never forget, and she doubted highly that Sokka had either. It was the moment she had realized that her father was human, and could make awful mistakes just as much as everyone else.

Hakoda had grabbed his ten-year-old son and shook him hard. He wanted to know why Sokka hadn't protected her, gesturing wildly at their mother still lying down on the ground as tears streamed down his face. He kept demanding to know if Sokka understood what he'd done. That he was responsible for this.

Katara had been unable to do anything, terrified of her father's anger and held tightly by her grandmother as the matron of their family yelled, in vain, for her son to stop this madness. Sokka had done nothing, had not even cried.

It had taken Bato coming over and grabbing Hakoda tightly to make him stop. He forced the other man to release his son, and once Sokka was free he ran. Faster than Katara had ever seen him go, he took off across the snow. Gran-Gran was too old, and Katara too small, to catch him and the two who could were otherwise occupied.

Sokka had returned at near dawn the next day, half-frozen and exhausted. He hadn't said anything to Katara as he stumbled in the make-shift tent the remains of their family had swiftly put up, and he didn't look over at where their father was sitting and their mother's body wrapped in animal skins. He'd just curled up next to Katara under the blanket and held her close.

He hadn't cried that day, or over the next few days as the funeral boats were being prepared. There was not a family in the village that hadn't lost someone, and most of the survivors couldn't bear to look at either of them. Katara suspected they were too much of a reminder of the children they had lost.

When their mother's boat was set in the water, Sokka turned and ran again. She'd moved to follow him, but Hakoda had stopped her with a hand on her shoulder and a shake of his head. Bato had glared at him, and gone after Sokka himself. She watched them from a distance as Sokka kicked snow and tried to hit the older man before finally collapsing against him.

Katara had known, right then, that she had lost her brother. He was still there but something about him, something important, was gone forever.

She'd been right to. He would still laugh and smile, complain and make jokes, but it wasn't the same. He would say them, sound like he meant them, but he wasn't really feeling them. He was trying too hard, and she could tell.

It had gotten better, as time had healed the scars. It had taken a couple of months, but Sokka began to act toward their father like he always had—and what had happened that day was something neither of them ever spoke about. Katara knew he hadn't meant, that Hakoda had been upset and angry, but sometimes she wondered if Sokka did.

And eventually he'd started to laugh again and really mean it, and his smile would reach his eyes. But there was, there STILL was, a wall between them that Katara could not break. Her brother started keeping everyone at arm's length. He was always watching people, always suspicious in a way he had never been before. There were so many things he wouldn't say.

Today, with Toph, had been the first time in six years Katara had heard him say anything about their mother.

Even now, he could change so fast she could never be sure of anything about him. Sometimes he seemed fine and happy, but would switch into a darker and more serious version of himself at a moment's notice. The brother she knew and adored who would smile, do his best to protect her, and habitually messed things up in the funniest possible way could instantly be replaced by a young man who could—and would—do whatever it took to redeem himself. He would take on any enemy, defeat them however he could…plan every detail of an invasion that would out hundreds of fire benders…endanger himself and all of them for the slim chance that he might gain some advantage over them. He had little regard for himself, or anyone, at those moments, and it frightened her.

Those were the times when he really hurt, and she could try her hardest to hold on to him, but it was like trying to hold on to the last wisps of a dream. He wasn't Aang. The closer she tried to hold him, the faster he would slip away.

All she could do was be there for those moments when Sokka was himself again, when he was teasing Aang or being a brother to Toph, and try to stop him from falling too far.

She had let him go once, and nearly lost him. She would not make that same mistake again—with him or anyone else.