The flash of fire is abruptly swallowed by earth. "If I'm leaving, I'm taking Uncle with me," Toph threatens. He was nice to her, and he's injured. She's not leaving him with his angry nephew.
"He's my uncle, not yours!" Zuko shoots another burst of fire towards her, but she deflects it with a rock wall, then opens the ground under him. Zuko falls into the hole, unable to react quickly enough to leap to safety.
"He's mine now!" She calls down to him, before sealing the earth over his head. She turns to the others, wishing for a moment she could see the awe that should be on their faces. "He's coming with us."
"Zuko? No way!" Sokka waves his hands in protest. "He's too shouty! We need sleep time, not shout time."
"I think she meant Uncle." Katara yawns. "I can't heal him all the way now, but we can bring him with us and I'll try after some sleep."
"But won't he miss Zuko?" Aang asks. He sounds nearly as tired as Katara.
"We can bring him too." Toph shrugs. They've got room, and it's not like he'll be a problem unconscious. Nobody says anything, so she elaborates, "He passed out. Not enough air underground for shouting."
Sokka is first to recover. "But there's a lot more air out here!"
"Then I'll make rock cuffs for him, and we tell him if he tries firebending we'll throw him overboard."
"We're not throwing anyone overboard!" Aang protests.
"Fine! Then Plan Guy can think of something!"
"Yeah, it's called not bringing them."
Toph stubbornly sits down next to Uncle. She's not leaving him, and they'll have to deal with that. "Then find a new earthbending teacher. I'm staying with Uncle."
"He's not even your uncle!" Sokka groans.
"He is now! Right of combat." She crosses her arms. "If Flamebreath wants him back he'll have to beat me, and that's not going to happen." She tilts her head slightly, bangs brushing against her eyes. "Especially if he runs out of air."
"Toph! He's going to die down there!" Aang sounds way too scared - it's not like she's going to let Zuko die, Uncle wouldn't want her to. Frowning deeply in concentration, Aang sinks into a squat, toes digging into the earth.
"You won't find him like that," Toph scoffs. She flexes her foot, and a slab of rock rises from the ground, an unconscious Zuko lying immobile on top of it. She can feel that he's still breathing, and if Aang was a better earthbender he could too. Instead, he does one of those airbending tricks that are invisible to her senses, stumbling as he lands. "See? He'll be fine. So are you bringing us or not?"
"Fine! Fine, we'll bring the jerk bender and his uncle-"
"-my uncle-"
"-but you're giving Zuko rock cuffs!" Sokka motions towards her.
She'd been planning on doing that anyway. As much as she loves a fight, she's not used to going so long without sleep, and once they're on Appa she'll have nothing to fight with anyway.
Zuko doesn't wake until they're back at the camp. This is both a good thing, because she didn't have to fight him while clinging to Appa, and a bad one, because it means sleeping is delayed again just when it was at her fingertips.
When he wakes, it's violent, his heart pounding like he's running up a mountain. "Uncle!" He tries to stand, but her rock cuffs keep him in place. He fights against them, but she just tightens them further around his weirdly skinny wrists. "Uncle!" He turns in the direction of Sokka's bedroll. "Where is he?"
His voice is raspy. She wonders if it's the suffocation, or if he just always sounds like that.
Toph pulls down the walls of her rock tent, and he turns towards her. "Calm down, Flame Brain," she tells him. "Katara's healing my uncle."
His struggles ease. Is he really accepting defeat so easily? She's disappointed in how much the others must have been exaggerating his 'chase the Avatar across the world' attitude.
Then he speaks, and she realises his mistake. "Who's your uncle?"
She grins wickedly. This is even better. "You've met him. Likes tea, has a really dramatic ex-nephew?"
It takes him a moment, but then he's struggling again, even more furiously than before. "Uncle is my Uncle! Not yours!"
"He's my Uncle now!" She cackles.
"You can't steal my Uncle!"
"I already did! You were going to make us leave without healing him. I'll be much better to my Uncle!"
"We don't need your help!"
"Too bad! Katara's healing him, and you're only here in case he still wants to see his ex-nephew!"
Zuko sputters, then raises his head to the sky and screams in rage, flame spouting into the air. Toph can feel the heat of it, and she's not impressed.
Neither's Sokka. He rolls towards them, his bedroll shifting against the ground, and groans, "What does it take to get some sleeping time around here?"
"Sparky's going to take another timeout," she says, and promptly earthbends Zuko underground again. WIth his legs and arms still trapped, he can't escape her, and the earth covers him before he can even turn his flame in her direction.
He passes out faster this time - he clearly hasn't learnt his lesson about firebending in a space with limited air.
Once he's out, she pulls him back up to the surface - right next to Sokka, because she can. He yelps, and she laughs.
"Is Zuko still asleep?" Katara is just coming out of the cave, and she sounds suspicious. Maybe she heard some of that.
"Yep," Toph says shamelessly. She doesn't need any of Katara's fussing right now, not since Zuko's going to be out for a while longer anyway. She just wants to sleep. To head off any more questions, she pulls up her rock tent around her.
"Good night?" Katara calls. Toph can hear her heartbeat, and it's steady.
Sokka's heartbeat is settling back into the slowness of sleep, which is pretty similar to Zuko's. She can barely feel Aang's, foraging food for the morning, but that's not unusual - he never stays grounded for long. Appa's is slower than any humans, easy to recognise, just as Momo's is fast. At the back of the cave is Uncle - his heart is a steady, thumping beat. Nothing like it had been.
With this symphony in her ears, Toph falls asleep.
Two days later, Toph takes Zuko with her into the cave where Katara's been healing Uncle. Uncle woke yesterday, and Zuko's been less belligerent since Toph told him. It's the only reason he's not currently wearing rock cuffs.
"Good morning, niece," Uncle greets her, and Toph grins at the jump in Zuko's heart rate. He didn't know about this. It's going to be glorious.
"Morning, Uncle!" She chirps, and she can feel Katara's tension rise. She's suspicious - rightfully so. Toph's not a morning person.
"Don't call him that," Zuko growls. His heart, already fast, beats faster. This is the first time Katara's let him come in to see his former uncle, and he's nervous. If anyone asks, Toph's just distracting him from his nerves. If they can't figure out how much fun she has riling him up, she's not telling. "He's not your Uncle."
"I told you, Sparky, right of combat. I beat you, so I took his uncleship. Now he's my uncle."
"It doesn't work that way!" Zuko immediately protests. "You can't just take my Uncle!"
"Can and did!" Toph's grinning extra wide, just to annoy him. She doesn't need to be able to see him to know it's working - she can feel the ground beneath him heating up.
She pushes it an extra step. She's always wanted to bend magma. "Isn't that right, Uncle?"
"My niece is right, Zuko. From what I've heard, she did beat you in a fair fight." Uncle sounds composed, if a little amused. He sounds like that a lot, and it makes Toph even more determined to keep him. Zuko doesn't appreciate what he has.
"A fair fight? She trapped me underground!" Zuko's heart rate is growing faster - he's really made, but no flames yet, and no magma. She'll have to try harder.
Katara gets there first. "If you still had your honour, maybe you'd know what a fair fight looks like, and your uncle would want to keep you," she mutters.
The acoustics of the cave take the quiet barb and carry it to their ears, echoing around them.
Zuko's heart rate rises, so fast she can barely hear it.
The ground under his feet is suddenly cold.
He bows perfectly, first to Uncle, then to her. "Prince Iroh. Master Bei Fong." His voice sounds strange, crisp yet lifeless. "I won't disturb you further."
He walks away.
"Zuko!" Uncle tries to follow, but he's still weak from the lightning. He clutches his chest.
Katara jumps up to support him before he can fall, bending the water from a nearby bowl and holding it to his chest. "You need to rest. He's just storming out, he does it all the time."
But that's not it, Toph knows. Zuko has reached the edge of the camp and hasn't stopped, ignoring Aang and Sokka's questions. He pauses long enough to scoop up his swords, then keeps walking on. His footsteps are even, but his heart is still too high, beating against her senses like a hummingbee.
She can't let him leave like that. Not when Uncle's on the ground behind her, whispering his name in tones of absolute anguish.
(Her parents never sounded like that for her.)
She runs out of the cave. Zuko's fast and is already long gone from the campsite. She keeps running, her earth sense telling her which way he's gone. Once she's close enough, she shouts, "Zuko, wait!"
He stops, but doesn't turn around.
"Uncle's my uncle now," she says immediately, because he is and she's not changing that for anyone. But… "But for some reason, he still loves you. And without him, you're apparently going to go off into the wilderness to die of drama."
"I'm not going to die of drama. That's not even a real thing," he snarls, but he hasn't started walking again. She's getting to him.
"So, I guess, you can share him." She almost adds a boundary, almost states that it definitely doesn't mean she's related to him just because she's letting him share her Uncle, but no. If she's going to do this, she's going all in. "Welcome to the family, brother!"
He chokes, and drops his swords.
"Time for a brother-sister hug!"
He backs away. "No. No! You're not my sister! No!"
She cackles, trapping him in earth and going in for the hug anyway. He's lived with Azula for a sister - Toph's an obvious improvement. He'll figure that out eventually.
Now, to go back and tell the others that Zuko's her brother…their reactions are going to be hilarious. This was the best idea.
(Maybe she can convince them that they've secretly been related this whole time. And with a brother as dramatic as Zuko, the whole walk back to camp should be plenty of time to convince him to play along.)