A/N: So I accidentally skipped a day, which means this drabble is a bit early. Hopefully you guys don't mind, especially because to make up for it, I'll probably end up writing a really long and elaborate smut (whooo!) Anyways, I want to thank everyone who has reviewed or faved or just thrown a 'good job!' my way. You guys are amazing and I love every one of you. Enjoy! ~TA

The first time they go out looking for Sky Bison, they are laughing. The second time they go forth, they are smiling. And the fifth time, Aang goes out alone.

It begins as a quest, something the Gaang volunteers to do, an adventure, a journey. They tear Zuko from his official duties, just for a little while; Toph shuts down her school for a bit, and Sokka brings out the old map and schedule, the almighty legacy of his life. They trace the paths of migration along the faded lines with their fingertips, and when they set off, the wind whipping through their hair, they're laughing, full of hope and excitement and that joy that comes with another adventure with friends.

They are gone for a month before they concede that there are no Sky Bison in the Eastern Air Temple.

But that's one of four, they reassure each other, boisterous still, happy and confident. There's three more out there, and the Fire Nation would never stoop so low as to slaughter the Sky Bison out of existence. Zuko swears that there's no record of such a thing, and the Fire Nation keep meticulous, if concealed, records. Somewhere, in this fast world, Appa surely has a relative.

Four months later, they are off again, travelling North, confident and excited, but on a deadline. The construction of Republic City has started, after months of deliberations and arguments, and the Avatar and the Firelord will need to be there.

"Plenty of time," Sokka says with a swagger, and off they go.

There are no Sky Bison in the North.

By the time they search the South, their very last destination, no one is laughing, and no one is confident. Their time is used up, and they've yielded no results. The journey forth is quiet and tense; the journey back is like a funeral. Aang doesn't say a word, doesn't acknowledge his pain, but it's so palpable that Katara fancies it a real being, sitting with them on the last Sky Bison, with the Last Airbender, in the world.

When they dismount, Zuko clasps Aang on the shoulder, and Sokka gives him a one-armed hug; they are sorry, so desperately sorry, for his pain, but they don't understand, truly understand it. Even Katara, the last Waterbender of the Southern Tribe, does not truly understand the grief that rolls off Aang like a wave.

He's only 19 years old, but he feels very much alone.

There are no more group searches for the Sky Bison, but Aang goes out alone, every now and then, when he's feeling antsy, when he's feeling lonely, when he feels things even Katara can't cure. He does it less and less often, now that they're married, but sometimes, there are days he needs to himself, and Katara accepts that.

They're sitting in on a meeting in Earth Kingdom. Construction is moving slowly on Republic City, and Aang is forced to travel, sometimes for months at a time, to each individual Nation, to oversee the removal of Fire Nation colonies and the restoration of balance.

The man who stands before the Earth King now has been accused of murder and arson, an angry man who doesn't want to leave his home. The sentence is passed, the guards come to take him away, and Aang hasn't said a word, hasn't made any judgement or sentence: he is only here to observe. The Firebender, however, stops before Aang's seat, pauses, and then spits in Aang's eye.

Katara is on her feet in a flash, and the Firebender is on his back with just a flick of her wrist; delegates are swarming over Aang, offering him napkins and help, and Katara is standing over the criminal with a face like thunder.

"Go ahead, help him out!" The Firebender yells. "It's not gonna matter much, is it? Give him fifty years, and that's the end of the Air Benders! Good riddance! Should have slaughtered them all when we had the ch -"

Katara's foot to his windpipe effectively ends the rant, but there is nothing she can do the wipe the stricken expression off Aang's face, and she knows it.

Late that evening, when they're washing up for bed, she is the one to suggest one more trip for Sky Bison, and Aang accepts.

They leave early the next morning, before the sun is up, flying aimlessly, because they're not entirely sure where they're supposed to go. There's the distinct feeling that getting their hopes up will only end in pain, but Katara and Aang are hopeful beings by nature, and the world is a big, big place. On a whim, Katara pulls out Sokka's map, leaning over to show Aang the different landscapes.

"You said the Sky Bison lived at the Air Temples?"

"Most of the time," Aang corrected, tugging slightly on the reigns. "They traveled between the four Temples, but on their own time. When it was time to mate, or find different food, or just because they felt like it, the Bison moved on. It's part of Air Nomad culture, the migrating sense."

"Never would have guessed," Katara teased him, leaning over to steal a kiss. "Well, we know there aren't any herds of them in the Temples, but where would they go when they migrated?"

"What do you mean?"

Katara pointed to the map. "It took us weeks to get from One Nation to another, even on Appa. Doesn't it seem logical that the Bison would stop and rest along the way? Especially the ones with babies - they'd need to have safe place to rest. There's bound to be places like that along the way; places the Bison have made a permanent home, if they don't think the Temples are safe anymore."

Aang frowned, his eyes a stormy grey. "That's a long shot, though, sweetie, and an even longer trip. We can't -"

"Can't what?" Katara challenged, resting her hand on Aang's knee. "Aang, if there's even the smallest chance that there's more of them out there, even just one ... don't you think that's a chance worth taking?"

Aang doesn't answer, but his grip tightens on the reigns and his eyes are hopeful, nevertheless.

Somewhere South - not entirely near the South Pole, but close enough - Aang admits defeat. They've been gone nearly two months, and there's no point chasing rainbows anymore. They'll rest on the nearest habitable rock, and then they'll head home. Katara wants to press on, wants to convince Aang that he can't give up, but, much like the time he lost Appa in the desert, Aang shuts down. Defeated, they settle for the night on a tiny little island, roll out their sleeping bags, and fall silent.

Around dawn, Katara awakes.

She's not sure what it is, but there is a feeling, deep within her gut, that tells her that something is wrong. It is a feeling that will serve her well in motherhood, but for now, it prompts her to ensure that her husband is still at her side. His skin is slightly cool to the touch, and Katara presses her hand against the flat of his back, reassuring herself that he is there, alive and safe. Yet something is still nagging at her, bothering her so much that she can't lie back down, and her eyes sweep the rugged terrain, wondering if they're about to be attacked.

And then she realizes.

Appa is gone.

For the hundredth time, Aang lifts the whistle to his lips, blows as hard as he can, waits ... and then exhales, bitter frustration and fear welling up inside him. They've searched the island for hours; he's taken to the sky, searched the sea for a ship, a mass, anything. Appa is gone. Appa is gone.

He squeezes his eyes shut, fist clenched tight on the handle of his glider, fighting the urge to decimate the entire island, and jumps down to where Katara is waiting, pale with worry. They've been searching for hours, now, and it will be dark soon. Their chances of finding him dissipate with every inch the sun drops in the sky, and then what will happen? He's going to lose his last true link to the Air Nomads, to his home, to everything. He's going to be sick.

"We're not done, yet." Katara tells him, brisk and stern, forcing herself to keep calm, to keep things together. "There's a cliff's edge over there that we haven't checked yet, and a little swamp to the left. I'll take the swamp, you take the cliff. If he's not there, we'll put out a distress call. We'll find him, Aang."

He doesn't really believe her, but he's been wrong before.

The cliffs are wide, rugged peaks, arching high into the air and then dipping dangerously low. Aang glides over the tops, swoops low to inspect the caves, and he can't help but think of the Western Air Temple; how the rock juts out, how open and free it feels. A good place to build a temple, if one were so inclined. He can imagine Sky Bison flying here, resting by the water's edge, eating all the food -

His heart skips a beat; there's a flash of white, moving briskly away, towards a sharp spike in rocks.

The wind whistles past him, a scream in his ears as he flies, faster and faster, heart pounding in his chest, mouth dry, and suddenly, he turns a corner, the sun is in his eyes, and -

- and he's surrounded by Bison, dozens of them, all flying together, looping through the air with an easy grace, white fur gleaming in the sunlight. Older ones, babies, females, all together, flying effortlessly through the air, and Aang, startled by the sight, starts to laugh, swooping over them, never wanting to fall back to earth again.

The swamp yields no results, and Katara is afraid to head back to camp, afraid that, this time, Appa is gone, really gone. She doesn't want to picture Aang's face when she tells him her news, but he's faced bigger hardships before. They'll find Appa, even if it takes them a hundred years.

A shadow crosses the ground towards her, and Katara glances up, squinting in the harsh light, mouth dry with apprehension. "Aang, I'm so sorry, I couldn't find -"

He pulls her towards him, and she's shocked to see that he's grinning. "Sweetie, you're going to need to see this."

The sun is slowly starting to sink when they touch ground again, and Katara releases Aang with a shaking hand, having done enough loops and twists and turns to send her brain spinning. Beside her, Aang takes her hand, pulling her carefully towards a little cave that she hadn't spotted before, tucked away into the mountain. And there, tucked away, is a familiar furry face, fast asleep, curled up next to what Katara suspects is a female Bison.

"He seemed to be in the middle of something, so I thought I'd give him some privacy," Aang whispers, and the smile on his face is ear to ear.

"Shame he can't pay us the same courtesy."

"Oh, I think he'll be a little more considerate, now that he's got a friend."

"A lot of friends." Katara tucks her arm around Aang's waist, looking out to the sky, where the Bison are still flying. "A whole lot of friends."

Aang's eyes are wet, but he's still smiling. "A whole herd of them, Katara. We can make a home for them, we can build a place in Republic City. He doesn't have to be alone, anymore."

"Neither do you," Katara reminds him, laying her hand against his cheek, brushing the tears spilling out off his face.

His kiss, when it comes, is feather-light and salty, and Katara takes it with pleasure.