A/N: I'm trying to get back into writing things outside of work, and since I've been sucked into the world of TMNT again, it seemed like a place as good as any to start; after all, it's where I began. This fusion is based on an art post on Tumblr (http (colon slash slash) tanya-buka (d o t) tumblr .com (slash) post (slash) 107688280130 (slash) crossover-series-with-tmnt-and-avatar). Basic knowledge of Avatar: The Last Airbender is helpful; I've kind of used a blend of 2K3 and 2012 for TMNT, though it's probably more heavily 2k3. (I also left it open to being a human!AU if needed…)

I've labeled this as complete because it is; if I do any more in this 'verse (if there's even any interest in this 'verse), it would be as a series of oneshots. Unbeta'd and I'm rusty at this, so take how you will.

Also, for this just go with the idea that the Avatar is four people instead of just one because it's cooler (and much more convenient) that way.

I own nothing. Title comes from Mumford & Sons.

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Know my name (as it's called again)

"Guys, so help me, if this turns out to be another dead end, I'm setting both your bunks on fire," Raph growls, shoving his hands deeper into the pockets of his coat and glaring out from underneath the biggest, warmest hat Leo had been able to find in the market before they'd left Omashu. "You can sleep on the deck of the ship and freeze, for all I care. Ain't right for anyone to be out here, let alone a fire bender."

Leo rolls his eyes, but doesn't say anything as he readjusts the scarf around his face, trying to block out the cutting wind. He and Raph have already fought three times this week - once with fists - and it's only Tuesday; he doesn't think his head can handle another "rock knock" from Don if he tries to split them up again.

"According to Sensei's instructions, we should be getting close," Don replies shortly, peering at the map in one hand and referencing the compass in the other. His shoulders are tense with more than just cold. For all Raph's complaining, Leo knows it will actually be Donnie who will take it hardest if their search turns up fruitless - Don had practically told him as much after the fiasco at the Southern Air Temple.

"I know you guys feel it, too - that missing piece," Don murmurs, staring out at the sunset beyond Omashu, motionless save for the three small pebbles slowly making loops in the air above his hand.

Leo swallows, his chest aching from more than just the bruised ribs he'd suffered yesterday, and nods. "It's better, now, with you and Raph around, but there's something that's just... not right. Like a part of me is..."

"Dead." The pebbles become dust without even a twitch of Don's fingers. "I know. I have dreams, Leo. It's dark, and it's cold, and I'm alone and so scared, and it feels like I'm drowning, and I have no idea what's going on. And I wake up and even though I know I'm fine, that I'm awake, that you and Raph are nearby, that you found me, I just - it's not enough, there's still someone missing, and I feel like I can't breathe because he can't."

Don turns to him, brown eyes gleaming bright with tears. "Leo, what if he's dead, and that's why we can't find him?"

And even though Leo knows his brother is still jumpy at unexpected movements (though not as bad as Raph), he doesn't hesitate to pull Don into a fierce hug, doesn't wince at the tremendous pressure on his ribs as Don reciprocates. "Donnie, you know we wouldn't be here if that were true. Sensei said-"

"But that was before the temple, before we saw what the Foot - there aren't any air benders left, Leo."

"No, Don," Leo corrects firmly. "There's one. And we will find him - no matter what."

"How can Sensei be sure?" Raph asks suddenly, yanking Leo from his memories. Raph shifts his weight from one foot to the other when his brothers stare at him, eyebrows raised. "I mean, we're on an ice cap - it's all water, and there's currents," he says, voice quiet. "How do we know he hasn't got it wrong, that things haven't shifted?"

"We have to trust him, Raph," Leo replies. "Sensei's visions may not always lead us to what we're expecting, but he's never been wrong about where to find what we're expecting."

Don stops, not even flinching when Raph nearly runs into him. "We're here."

Leo blinks, then looks around. The wind has picked up, sending snow whirling into the air from where it's drifted across the ice pack. Behind them, he can just make out the distinct lines of the Fire Nation ship they've been using for this leg of the journey. To the left are the bluffs marking the edge of the Water Tribe's territory; in front of them not even one hundred paces is a sharp drop that leads to the sea, filled with giant chunks and bergs of ice.

But other than a cluster of otter penguins gathered on one of the icebergs and his brothers next to him, Leo doesn't see any sign of movement. No sign of what they've come for.

"You sure this is the place?" Raph asks skeptically. "I mean, it ain't like there's much separating this snow drift from the eighty other ones around us."

Don frowns, rubbing his forehead in thought, and looks at Leo. "We're standing on water - and you've been training with April..."

Leo nods, kicking some snow aside to reveal the ice pack beneath as he yanks off a glove and kneels. He sucks in a breath and pulls his hand back instinctively at the bite of the cold ice on his skin but forces himself to regulate his breathing and concentrate.

"It's not like seeing, really," April says with a shrug, cloudy eyes staring right at Leo as she wiggles her toes in the mud of the riverbank. "I mean, I use it to see, and it's how I've always seen, but I don't think that it really translates the same. For you, it would be more like... you know how Master Splinter tries to get you three to attack him while he's not looking, but he almost always knows when you're going to hit him?"

"So it's like sensing," Leo muses. "Of a sort."

April shrugs again. "Like I said, it might not even be possible to do it with water. Earth is solid, harder to move. Vibrations travel much easier because of the cohesion. But water...well. I'm the only earth bender I know that can do this, and it's because I've had to learn how," she says, waving a hand in front of her eyes.

"Well," Leo says, closing his eyes and letting the gentle movement of the river around him fill his senses, "I certainly won't know until I try. And besides, sometimes water can be just as solid as earth."

It hadn't worked then - not that Leo had told his brothers that. But he hasn't tried it on ice before, and if Master Splinter is right about what's hidden underneath this ice, then Leo has an extra advantage. Because not only does Leo want to find what they're looking for, but it wants to be found.

He closes his eyes and presses his palm flat against the ice. The innate power in his blood springs to life at the feel of water beneath his skin, but he tries to redirect it - to let it flow down and spread out through the ice, instead of trying control and bend it.

"If he really is trapped in ice..." he hears Don murmur.

"Then we'll get him out," Raph says firmly. "It's not like you were any easier to rescue - or Leo, for that matter. It'll be fine, bro."

Leo lets his brother's confidence bolster his will. His breath catches when he suddenly finds something - the broken hull of a small wooden ship, he's pretty sure, trapped in the ice. April's right - it's not like seeing - but Leo was wrong; it's more than sensing, more than feeling. Leo's not sure how to describe it; it's beyond words.

"Leo?"

Leo raises the hand that's not touching the ice to stave off his brother's questions - he's not even sure who spoke at this point, so intent is he on seeing deeper into the ice. He can see the vibrations rippling through the ice as one of his brothers - metal-reinforced shoes, the ones specially designed for Fire Nation soldiers to use in battle without having to walk barefoot, so it's Raph - takes a step closer - there's hands on his shoulders now, one on each side, Raph and Donnie anchoring him as has become custom these last two years - but Leo ignores them for a moment because there's something... something he can't find but he knows is there, he just has to push - a - little - more -

There.

There's a collective gasp as power suddenly surges through the ice, up Leo's hand, through the three of them. It's sharp and powerful and nearly overwhelming and so warm and right, and for the first time since he awoke two years ago to the sight of Raph's worried face and with the knowledge that he's one part of something more, Leo feels whole.

The ground beneath them shudders violently as the ice splits with an ear-splitting crack, and Leo doesn't even think, just moves his hands instinctively and shoves, using his bending to push himself, Don, and Raph back. He opens his eyes in time to see the ice in front of them drop away with a rumble. In the distance, the otter penguins squawk and splash into the sea as a tremendous wave spreads out, propelled by the shifting ice.

There are still hunks of ice and puffs of snow falling from the newly formed cliff, but when Leo looks over the edge and sees there's still a chunk of ice thirty feet below them that's large enough for them to stand on, without a thought and lands silently, Don and Raph following just behind.

They turn to stare at the newly revealed ice wall. And stare. And stare. "Whoa," Raph breathes finally.

The newly revealed ice in front of them is clear enough to make out a huge, hulking shape encased in it, far enough below the surface that it's apparent it's been there for a long time.

"Is that... him?" Raph asks.

Don huffs and plants his feet, thrusting his arms forward. The rock bands around his wrists shift as they fly off, becoming long, razor-sharp spikes as he drives them deep into the ice. Leo follows his lead, pulling away the ice that has loosened thanks to Don, and Raph uses fire bending to soften the ice, letting Don's earthen spikes drive even deeper into the ice.

Then there's a surge of the power again, and suddenly Leo knows his eyes must be glowing because within the center of the strangely shaped mass, a pair of eyes opens, shining brightly out of the darkness.

A tremendous blast of air nearly blows them back off their feet as more of the ice suddenly gives way, revealing the giant pocket of air that had surrounded the figures in the ice.

And it is two figures, because Leo can see them both now, clearly. There's a giant sky bison - which, Leo normally would be ecstatic because he's always wanted to ride one and he thought they were extinct; but this one's alive, he can see its great chest heaving now.

And yet, it doesn't hardly register because there, slumped over against the sky bison's side, nearly buried in its thick fur -

Raph's already there, gathering the body into his arms. Leo exchanges a look with Don as they scramble over the remaining distance, because they've both been there before - Leo might be the leader and technically the oldest, but Raph is always, always the one there when they first wake up.

"Easy now, bro, we gotcha," Raph murmurs to their brother, who's stirring and whimpering as Leo and Don kneel down next to them. "We gotcha, it's me, you're safe, I promise, okay? You're safe now, we're all here - me and Donnie and Leo, we're not going to let anything bad happen to you now."

Don's eyes are wide as he gently rubs a gloved hand over the arrow tattooed on their brother's forehead - the mark of an air bender, quite possibly the last one, Leo thinks - and Leo feels like his heart is about to leap out of his chest as he grabs one of his brother's hands.

Then his brother's eyes open; years later, whenever he's asked about this exact moment, Leo swears every time that there was an audible click of the final, long-missing piece of the puzzle falling into place. Of his family finally becoming whole.

Leo grins, perhaps the broadest he's ever grinned, as those wide, blue eyes blink and look at them all - confused and haunted and yet so hopeful - and a name springs to his lips, forgotten until this moment and yet as natural as anything rolling off his tongue. "Welcome back, Michelangelo."

End