A/N: Yay, I finished this! :D Raberba girl said anything with Axel and Saïx would be good when I asked her what she wanted for her giftfic, and this was what I came up with. Somehow.

It's not that important, but in this 'fic Saïx is somewhere between a few months and a year older than Axel, and it's set before Roxas and Xion are in the Org.

Hope you enjoy, !

"Hey Saïx, do you know what day it is today?"

Saïx stubbornly ignored Axel's question. It was difficult enough to focus on typing out mission slips this late at night without anyone pestering him.

"C'mon, Saï, stop being such a workaholic for a few minutes and listen to me." Axel waved a hand in front of the computer screen, causing Saïx to growl at him. "It's really hard to resist making a werewolf joke when you do that, you know. But considering what day it is, I'll try a little harder."

"It should be quite simple, without any heart to compel you to make such ridiculous comments." Saïx continued to type despite the interference.

"Ouch, that was rude." Axel pretended to look offended.

"But true."

"Whatever." Axel sighed. "You must really not want to go through with our promise."

"I can hardly see a point to it anymore," Saïx said softly.

Axel gaped at him. "Since when does keeping a promise need a point? Besides, we've barely had any time to hang out since you took over assigning missions from Vexen, and it'll be fun."

Saïx finally stopped typing, resting his still fingers on the keyboard. "Do you believe we are still capable of having fun?"

Grinning, Axel pressed the power button on the computer to turn it off.

"Why don't we find out?"

He grabbed Saïx's arm and yanked him out of the chair, dragging him through a dark corridor.

XXX

The old treehouse just outside the urban area of Radiant Garden was remarkably unchanged despite the city's transformation into Hollow Bastion. The tall, thick magnolia, the leaf-strewn clearing, the weathered wooden structure, it was all the same. Even the stars seemed to shine just as brightly as before the world was plunged into darkness.

Saïx and Axel were awestruck.

"It's still here," Saïx said in disbelief.

"Yeah," Axel agreed in a near-whisper, then grinned. "Race you to the top!"

Saïx rolled his eyes. "Are you determined to act as immature as ever, L- Axel?"

Axel had already hoisted himself into the tangle of branches. Laughing, he poked his head out through the leaves.

"Are you determined to be a fun-sucker? You don't have to keep up the grouchy werewolf act here. C'mon!"

Not bothering to see if Saïx was following or not, Axel navigated the maze of branches with ease, remembering the path he mapped out years ago as if it was yesterday. A few of the weaker limbs bent and creaked more when he put his weight on them than they used to because even though he was still ridiculously thin, he had grown since the last time he climbed the magnolia. Despite their protests, the limbs didn't break.

Sighing, Saïx swung himself up from a lower branch, but a phantom smile tugged at his mouth. It grew wider as he leapt from limb to limb, leaves whipping his face, a breeze blowing his hair, the fact that he was a Nobody and should technically not be able to enjoy the climb the way he used to forgotten.

Axel grinned at his friend below. "C'mon, you're faster than that!" He took off through the higher branches, Saïx speeding to catch up though he knew it was pointless. Axel always was faster than him.

Finally, Saïx pulled himself over the edge of the platform of wood planks. Axel was already waiting for him, yawning exaggeratedly.

"I don't think being a Nobody's done much for your speed."

The reminder of his current state blurred Saïx's memories of his past feelings, and his smile faltered. "We could have used corridors if you wanted to get here quickly."

Axel shrugged. "Nah, where's the fun in that?"

For a few moments they were silent, staring at the structure they'd built together ages ago. It had a rounded opening for an entrance, which was now too short to go through without ducking. Paneless windows lined the walls facing away from the tree, and branches hung over the open roof, forming a natural ceiling. Axel's brother had helped to design it, but the young Lea and Isa (mostly Lea) were too proud and confident in their own handiwork to accept assistance with the actual construction. As a result, a lot of the boards were extremely crooked, creating gaps in the wooden walls. The only reason it had any stability at all was that Axel's brother had secretly come and nailed down most of the planks. Isa and Lea chalked it up to the 'Forest Elves' deciding to help them, and they wouldn't turn down help from magical creatures and risk making them angry.

"I can barely believe this thing has managed to remain standing," Saïx said, ducking inside.

"I'm glad it has. Remember all the things we'd do from here?" Axel ducked in, tapping a fist on the wall. "That time with the kite…"

"You nearly got us electrocuted," Saïx said. The remains of the red cloth kite had never been found – luckily they'd let go of it before a lightning bolt shot it to the ground.

"Good times, good times." Axel smiled wistfully. "That wasn't the only thing we tried to fly, remember?"

"The hot air balloon." Saïx nodded. "That's why we're here, is it not?"

Axel dragged a giant basket of red-and-navy fabric out of the corner of the treehouse. "So you did get our promise memorized!"

"I knew you wouldn't allow me to forget." Saïx had been wondering when Axel would try to kidnap him and bring him here. Frankly he was surprised (and maybe slightly disappointed) as a Nobody could be that Axel hadn't brought him to the treehouse sooner. "We promised to have it finished by my twenty-first birthday." Saïx stared at the hot air balloon pieces, which were actually a laundry basket and a torn parachute.

"Yep, and that's tomorrow. We were going to have one last blast before we're legally sucked into the grown-up world. We still will, if we finish it tonight."

Saïx frowned. "We are not children anymore."

They had dreamed of using the hot air balloon to reach the moon and the stars. Now they could travel the stars, the other worlds, with ease through dark corridors, and Saïx had the power of the moon with all its advantages and disadvantages at his disposal. They didn't dream anymore. They had grown up.

"A promise is still a promise," Axel argued.

"I doubt it will work. We know next to nothing about aeronautics."

"That's not the point."

And it wasn't really Saïx's point, either. He didn't care if their balloon failed; he was more worried about what would happen if it worked. If they did touch the sky for a moment, and he couldn't feel any emotion about the experience, it would ruin everything he dreamed of as Isa.

"We promised to try," Axel continued. "What've we got to lose by trying?"

"I could lose," Saïx whispered, "what I imagined it would feel like."

Axel's expression softened. He didn't think Saïx bothered to imagine anything anymore.

"Hey." He clapped Saïx on the shoulder. "Y'know, you look awfully depressed right now. Are you sure you can't feel anything? Maybe there's something still in there."

Saïx shook his head. "There's nothing but emptiness."

Axel sighed. "I wonder if it's just that we've been told that so much we believe it. If we tried, maybe we could still find a link with wherever out there our hearts are. After all, they're not gone forever."

Could it be true? Would trying make any difference?

"If we tried to feel…" Saïx muttered with a hint of a smile. "I suppose… It wouldn't hurt."

The hot air balloon might not live up to his expectations, but he wouldn't know if he didn't try. Had he ever tried before?

Axel grinned widely. "Then let's do this."

He quickly opened a trapdoor in the bottom of the treehouse and hefted out a dusty device.

"Your sister's old sewing machine?" Saïx asked.

"Yep. I still remember a few things Alexa taught me, and I did take that home ec class, even if it was just to get an easy A." Axel blew off the layer of dust, wiping a few spots with the edge of his coat.

"Do you recall enough to repair the hole on the balloon?"

Axel shrugged. "We'll see."

Luckily, the old machine was battery-powered, and there were spare batteries lying in the bottom of the secret compartment where it had been stored. It was still threaded from the last time Alexa had used it before Lea stole it to take to the treehouse, so Axel didn't have to remember how to do that.

Saïx helped as much as he could as Axel worked the machine. 'As much as he could' in this case was keeping the parachute from getting tangled up, but he still helped.

"That is the worst sewing job I've ever seen," Saïx commented once the hole was mended.

Axel held it up and examined it. "You think you could've done better?"

"No," Saïx admitted. He had no siblings to teach him random skills, and he never took throwaway classes. "But I still don't trust that thing to get off the ground."

"Heh, we'll see about that." Axel grinned, tugging slightly on both sides of the ugly-but-strong seam. "Now we just need to attach the parachute to the basket."

"Which looks much too small to fit both of us now…"

"Oi, have a little faith, Saï." Axel began tying the parachute strings to the loops on the woven basket. Saïx shook his head but joined him.

He wouldn't admit it, but he was just a tiny bit curious as to how the hot air balloon would turn out. Maybe he really did want it to fly.

"Wanna make a bet?" Axel asked with a mischievous grin.

Saïx snorted. "If you bet that the hot air balloon will fly, I'll accept." Wanting and believing were two different things. Regardless of what Axel said, Saïx didn't think it would make it off the treehouse platform.

"Loser buys ice cream?" Axel asked, holding out a hand to shake on it.

"Who said we're getting ice cream?"

Axel grinned. "I did."

Saïx rolled his eyes and shook he hand.

"Nuh-uh," Axel said, waving a finger. "Our other handshake. The secret one."

"You still remember that?" Saïx wondered if the complex motions were still stored somewhere in his own memories. It might be hard to get them out.

Axel tapped his temple. "I got it memorized. What about you?"

Thinking intensely, Saïx held out his hand. They went through a complicated series of high-fives from in front and behind their backs, two games of thumb war, multiple fistbumps, and cheesy sound effects of explosions, all together lasting over two minutes. Afterwards, they both laughed slightly.

"I can't believe you remembered," Axel said.

Saïx smiled. "I have it memorized as well."

Axel laughed more at that. "C'mon, let's test this baby out!"

They dragged the balloon out to the platform outside the main treehouse, and Axel lit a hovering fireball. It was much simpler and more likely to work than their original plan of holding a torch to heat the air. Saïx lifted up the parachute to let the flame in, and to his surprise, the fabric billowed up from the heat.

"So far so good," Axel said, hopping into the basket. Luckily it was the basket that once held his family's laundry, and with as many siblings as he had, there was a lot of laundry.

Still, Saïx didn't trust it to hold both him and Axel. Even though Axel was thin as a twig.

"Are you sure about this, Axel?"

"Not at all. C'mon!"

"This is the dumbest thing we've done in years…" Saïx muttered. At least if the balloon crashed, he reasoned, he might have time to open a corridor, and if not, he had plenty of elixirs. Besides, Axel would never let him live it down if he chickened out. He would just have to hope the ride would live up to his expectations and not end in horrible disaster. That was a lot of hoping for him.

He climbed over the edge of the basket, setting his doubts aside. There wasn't much space left, but they weren't squished. He'd somehow managed to underestimate Axel's twig-ness.

"Exactly! Aren't some of our best memories of dumb things we did?"

"I wouldn't call them the best memories."

"But you remember them, right?" Axel grinned, increasing the fireball to the size of a watermelon.

The basket creaked in protest, the strings pulled taut, the air heated to a scorching summer day even though it was the middle of the night, and the awkward homemade hot air balloon rose off of the platform and away from the magnolia tree.

Despite Nobodies being supposedly unable to feel surprise, Saïx's jaw dropped. Axel smirked smugly.

"Told ya we'd get it to fly. You feeling something now?"

Saïx blinked up at the stars that they were sailing through. "I'm not certain, but… I think I'm enjoying this."

Axel nudged him in the ribs. "See, you need to stop overworking so much and live a little."

Not bothering to reply, Saïx let himself smile. They hung above the treetops, breathing in the warm night sky and finding constellations for a brief moment.

Then the balloon combusted.

Saïx wasted no time panicking; he opened a corridor inside the basket and pulled a stunned Axel through. They came out back on the treehouse platform in time to see the hot air balloon crash and burn through the branches below.

Axel ruffled his hair, putting out the fire. "Eh heh…"

Saïx smacked him upside the head. "That's why we don't enact plans we concocted ten years ago."

"But you had fun for a few seconds," Axel said. If it wasn't for his fire being magical, it wouldn't have lasted even that long. "Wasn't it worth it?"

"Well… I don't regret hanging out with my best friend again," Saïx admitted with a slight smile. "That doesn't change the fact that your plan was idiotic."

"Sure, whatever." Axel didn't care. He figured it would fail from the beginning, but a promise was a promise, and it was worth it to get Saïx away from his work for a few hours.

"You are not to tell anyone we did this," Saïx ordered. Axel saluted mockingly.

"Of course, sir."

Saïx rolled his eyes and opened a corridor.

"Wait, where are you going?"

Turning to Axel, Saïx smirked the same was his friend always did.

"You owe me ice cream."

"No way! The balloon flew!"

"And then fell to its demise."

"Minor details." Axel waved a hand. "But, since tomorrow's your birthday, I'll buy anyway."

Saïx rolled his eyes. "You just want the bragging rights, don't you?"

"Heh, you've got me there," Axel admitted.

"Keep them," Saïx said unexpectedly.

"Huh?"

He smiled. "You deserve it. You reminded me what friendship means."

Axel clapped him on the back and grinned. "Any time, Saï."

A/N: The treehouse and Axel's family are a reference to "Whatever You Want to Do" (one of my other fanfics), but they're not in the same universe.

This was vaguely (EXTREMELY vaguely) inspired by the song "Hot Air Balloon" by Owl City (I've been listening to way more Owl City music than is healthy recently). The actual song has a completely different mood and would actually fit a SoKai story; I just needed an idea for what Axel and Saïx were going to do once they got to the treehouse.

I think that's all I've got to say about this, other than that I greatly appreciate reviews. They're the main food source of my muse.