This one is more AU than normally.

"How did you know?" Mai's tone was as flat as ever, but Toph heard the thumping of her heart increase as the older girl shifted back.

It was a strange thing she was doing, she knew—talking to Mai in the middle of battle. A couple feet to her right, Katara and Aang were pushing back Azula, and Sokka was holding his own against Zuko. She could feel the fury with which her companions fought—could feel her own body quivering with the urge to join them. But this, this could change everything.

"You move the same way Twinkle-Toes does," she explained, keeping her focus on the knife-wielding girl, "Both of you."

The acrobat—Ty Lee—gave a small gasp, but her heart was steady. She knew that I knew…or suspected. Interesting.

"What are you going to do with the information?" Mai again. Toph could feel her reaching for her knives. She shifted her weight, pushing on the earth as she jabbed her fists forward, and both girls were encased in rock.

If she'd been able to see the two girls in front of her, Toph might have noticed the signals they were flashing at each other with their eyes.

What do we do? Can we bluff it?

She can tell if we're lying. Maybe we should just—

No. We can't. Azula would kill us.

Then what?

"I'm not going to tell your boss. Not yet." Toph's voice broke into their silent conversation. "But I want to know what happened. Aang deserves to know that he isn't the last Airbender left."

We know how that feels. Remember how happy we were when we realized we weren't the only ones?

I was happy. You wanted to jump his bones and repopulate our tribe.

Yeah…I still kinda do. Too bad he's like, twelve.

A pause.

So you think we should tell her?

I always liked her. The Waterbender too. They never tried to break my arm like 'Zula does when she spars with me. And her brother's cute.

Such flawless reasoning.

Mai—

Fine. Let's tell her.

"We don't remember much," Mai said, eyes fixed on the blind girl in front of her. "Ty Lee and I—we were just kids. She was only three, I just turned four." She watched the girl. "You know I'm telling the truth." The Earthbender nodded, and Mai continued.

"The raid came on my fourth birthday. She was the only girl even close to my age, and our parents forced me to invite her to my 'party.' We were eating cake when the fire started falling." Her eyes flashed cold, and then hot, and then returned to smoky ashes.

Ty Lee sensed her best friend's hesitation, and as she always did, filled in what Mai could not. "We saw our parents die in front of us. Our house fell, and they were crushed underneath. Mai and me, we were lucky—we managed to crawl out through a small hole. That's when 'Zula found us."

"The guards around her wanted to kill us, but she ordered them to stop. She said she wanted personal Airbender servants—the last of their kind." Mai finished. She flinched back as a wall of flame flew over her head as Zuko's shot went wild.

Idiot.

You love him.

That doesn't mean he isn't an idiot.

Their bonds loosened and formed a thick wall of rock. The two girls watched as Toph pushed the wall straight into Azula, effectively blocking the circle of flames she was aiming at a fallen Aang. The blind girl looked back at them as she started for the fallen Fire-Nation Princess. "You can join us you know. One day someone else will wonder how your knives can penetrate steel from yards away and how Ty Lee's punches can throw a man through walls."

Should we?

Azula will never let us escape.

They have the Avatar. And, they've managed not to get captured so far.

We'll be branded traitors.

Oh yeah…I'll never be able to kiss that Lord's son—what's-his-face…and you won't be able to marry Zuko.

I never said I wanted to.

Mai…this is our chance. We can stop helping Azula kill all these people. We can stop hurting innocents. And I can get a chance with that cutie Water-Tribe peasant.

Again, flawless reasoning.

"Well?" Toph started to turned around, ready to rejoin the fight. If Sweetness didn't stop fussing over Twinkle-Toes and watch her back, she'd lose that pretty braid and probably most of her dress too. And then suddenly, the two girls were by her side.

She could feel the little puffs of air that made their steps as light as Aang's, the way they left no footprints when they wanted to move undetected. And then she could feel them tearing forward, attacking the girl they'd served for over ten years.

"Well," she thought wryly, "This should change things up a bit."