Zuko followed the tunnel to its end and stopped to look down into the massive cavern. Massive softly glowing crystals and several calm rivers filled it with what would have been a nice ambience were it not for the three benders disturbing the peace. He watched, oddly detached, as his little sister held her own against a master waterbender in her element and the three element wielding Avatar.

But then she started losing.

He could almost see the moment her foes realised they would beat her, though they weren't foolish enough to give her any chances. She was Azula, after all. They pushed her back and flanked her, then abruptly they all paused, a temporary standoff.

Zuko moved to join the battle before pausing. Azula wasn't winning. Azula always won. And she always had an audience. Where were her Dai Li agents? She had been flanked by more than a dozen of them when she came for he and uncle, but she faced the Avatar and the waterbender alone? With no one there to witness her victory?

She knew he was there.

He could almost laugh. Of course she knew he was watching. Why else would she hold the standoff like that? She was waiting for him to swoop in and play the role he had always wanted; big brother.

She could have won using her Dai Li puppets, but she wanted his help. Why? To turn him in just afterwards? She already had him in her custody. 'Accidentally' kill him in the confusion of battle? There were far better ways and she knew that. He couldn't think of a reason. There had to be a reason.

But then it didn't matter.

Azula, his little sister, the only living family member who hadn't scarred him in one way or another, wanted his help. Enough to fight a battle she couldn't win alone, when she could have had all the back up she could need, just so he would come to the rescue.

She needed his help. She wanted his help.

Zuko leapt into the fray with a vengeance, both legs kicking a massive blast between the Avatar and his sister as he flipped back, using the kickback to soften his fall to land just as the blast dissipated with swirls of... blue?

All eyes turned to him, surprise and shock absurdly evident on all faces. Then everyone moved at once and the battle began anew.

Rapid blasts of blue shot from his fists straight to the startled airbender, who barely blocked the first shot, then dodged and flew off to gain distance. And his breath. Just great, another freaky blue firebender.

Zuko for his part used the time to observe the blue flames blazing on his palms. They were... beautiful. A tighter, more compact fire that burned hotter and had much more force to it. He relaxed his control in his left hand, usually enough for the flame to go out, and watched the flames dissolve into the usual swirl of red and yellow. It was still beautiful and deadly but it just felt somehow... lacking? Small? Cold? He twitched his hand and the flames burned blue once more.

Surprisingly, it felt more normal. Better. He let the flames meet between his hands, held them charging there, then let loose and watched it fly towards the rocky barriers his opponent was hiding behind.

It tore through the first and exploded against the second, sending the Avatar sailing back to crash down, hard. Zuko stalked forward, wary of his downed opponent. Past experience had taught him better than to think this fight over, so he moved in an arc and kept his eyes on the man-made crater.

The Avatar wasn't moving. Zuko paused a fair distance away and risked a glance to see how his sister's battle was going. Surprisingly enough, not so well. He could tell she hadn't fought a waterbending master near a large body of water before, and so she was making mistakes. Her arm and then her leg were encased in water-tentacles and she was panicking. She needed help.

So he helped. Another few seconds and it would have gone badly for her, but he sent a slash of blue to cut and evaporate the water to free her. Azula actually flashed him a thankful smile before joining him in attacking the audacious waterbender. They soon had her entirely on the defensive, but she had moved into the river and was surrounded by her element. It was still only a matter of time but she was putting up quite the fight. They almost had her beaten down when a burst of light distracted all three.

Back where the Avatar had fallen, a crystal tent was glowing with that same light that had become so annoying to him. The Avatar was about to emerge, tattoos and eyes glowing, with more power than was natural. Zuko frowned and moved, ready to attack the moment he showed himself.

Azula realised what was happening and gestured her Dai Li down from their hiding places. Half surrounded the waterbender and half moved to flank the glowing tent. Azula moved away to get a clear shot of the Avatar. They all waited.

And then the crystals exploded in a rush of earth and wind. The Dai Li were knocked down and scattered like leaves while Zuko managed to keep on his feet by conjuring a barrier of fire, even then he was pushed far back. The Avatar rose, bright with power and unnervingly impassive and unstoppable like some god of a forgotten age; not even looking at the mere mortals before him.

The prince froze for a moment, awed as always by the raw power contained in that little airbender, now set loose. And then he straightened and moved to knock him out of the sky before they were all killed. A tight sharp lance of blue fire sent with all the speed and force he had went rocketing straight for the still rising god's chest, but once again his sister showed him up.

Lightening flew faster than fire and struck down the Avatar, just in time for his lance to fly overhead and pierce through metres of solid rock instead. The siblings looked at each other then; him in surprise and then bemusement at his surprise, her in shock with not a little respect for his unusually fierce attack. Then they looked back in time to see the falling god crash into the waterbender's arms.

No one had seemed to know what to do, it seemed unreal, and the waterbender took advantage of their distraction to knock those surrounding her down and launch herself towards her falling hope. The wave carrying her was massive and swift, too fast and strong to be stopped by the startled Dai Li.

She caught her friend and laid him down gently, tears flowing as freely as the water swirling around them. Blue fire struck several times only to be effortlessly blocked by the massive amount of water being constantly fed by the river. They wondered if she even knew they were attacking.

Just as they moved to close in, orange fire blasted the ground between them and their target, followed quickly by their uncle. Iroh shouted something to the waterbender and defended her as she retreated on a pillar of water, the Avatar hanging limply in her grasp.

His words were lost on Zuko. The prince stared at his uncle the complete stranger before him, the stranger standing between him and his way home. The man who had apparently been sabotaging his efforts for three years, while they saved each other time and time again. His uncle who now looked at him as if he were simply an enemy to be defended against.

He ignored Iroh for the moment and tried to stop his prey from escaping, but a wall of red fire blocked his attacks, and they got away.

They got away again.