A/N: Whenever I write a scene like last chapter where a piece of science or rationality is explained, I'm always faced with the problem that Naruto would not know that much science to begin with. If he did I would have liked to explain the concept of a scientific explanation: Namely that instead of trying to think of reasons why a phenomenon should exist, the goal is to describe in the simplest possible terms what's already going on. The idea that describing *how* something works is exactly the same as explaining *why* it works is an incredibly important insight which I think even people with a scientific background don't really grog intuitively.

Similarly, Naruto said last chapter that you can change the nature of chakra simply by pushing it into a certain physical shape. He concludes this because e.g. the summoning technique can be cast either by focusing chakra to your hands and making a physical sign with them, or by writing a specific shape with chakra-infused ink (i.e. a seal). That may sound weird and arbitrary, but there's actually a real world parallel here: Atoms work more or less the same way. Just by adding or subtracting a proton you can create a completely new element with totally different properties. That's always seemed like magic to me, so I figured if it sounds like magic IRL it's not too much of a stretch to have actual magic work the same way.

"You want in?" Naruto stared at the older sister of the boy he had murdered, uncomprehending. "What do you mean, you want in?"

"I mean I want in," Temari said, shooting a glance at the stylistic wall paintings that lined the main hall of the Uchiha shrine. "I want to take part in your little exchange. This is a ninjutsu trading scheme, isn't it?"

Sasuke pressed the seal to close the door, nearly crushing her younger brother in the process. "What gave you that impression?"

Temari blew a sandy blond lock out of her face, causing it to flutter up and fall back in line with the rest of her bangs where it belonged. "Don't act coy with me, pretty boy. Or was that for the benefit of your Hyūga minders?" She folded up her metal fan and sheathed it in the leather holster on the back of her black kimono. "Having to hide from your own people… how pathetic."

"You want to trade techniques with us?" Naruto looked around at the others, searching for any sign that they thought it as mad as it clearly was. "But we fought each other during the chūnin exams. How can you possibly want to trade with us after I ki-"

Sakura yanked Naruto back by the shoulder, nearly causing him to stumble and fall. "What my friend is trying to say is that we wouldn't want to get you into any kind of trouble. Surely the rest of your Village would not be too happy if you shared your secrets with us?"

Kankuro sniffed loudly. He had changed up his theatre-style purple face paint to look slightly more intimidating than the last time. "Don't lump us in with the rest of you Leaf types. We're the children of the Kazekage: There's nobody in the Sand who'd dare tell us no." He scratched the top of his head, causing his black hood to droop to the side and making him look decidedly uneven. "Well, uh, except for our father of course, but he's really busy and probably won't notice."

This was the psychopath who had made Tenten run away in abject terror during the chūnin preliminaries, Naruto was forced to remind himself. He glanced towards Tenten, but the mousy girl had set her jaw and was staring back at the puppet user defiantly.

She was still holding on to her giant siege crossbow.

Neji crossed his arms. "And why would you want to trade secrets with us? Even if you were to learn our techniques, you'd end up revealing your own weaknesses as well. It gains you nothing."

"That's why I said not to lump us in with you guys," Kankuro said, adjusting his oversized black hood. Those folds at the top were supposed to be ears, Naruto realized in shock. And those purple stripes on his face… whiskers? Was the guy actually dressed up as a cat? "Unlike you, we grew up in the dessert: A barren wasteland where the weak die and only the strong survive. Even if you learn our secrets, it won't help you one bit!"

"I thought you grew up in a palace," said Sasuke.

Temari shot him an annoyed look. "You'll find that our courts are more deadly than most arenas. Not that you would understand, of course, being without a clan to teach you these things." She jerked her head towards Neji. "You can call off your henchman now, white eyes. We're not here to fight."

Neji gave the smallest nod. "You can come down, Lee."

There was an almost inaudible thump as Lee dropped down from the ceiling behind the Sand ninjas, landing on all fours with a kunai still gripped in his right hand. "Yosh! We'll give you the benefit of the doubt, then. Welcome to our secret meeting, foreign friends!"

"Uhm," said Hinata, "I'm not sure we can decide that yet." She flinched ever so slightly as everyone turned their attention on her. "I mean, it all still seems a bit… strange. Don't you think?"

Sasuke and Sakura glanced at each other, though Naruto was honestly not sure what the glance was supposed to convey. His teammates might both consider him 'unbearably naïve', but when it came to trusting ninjas from a foreign Village whose sibling he had murdered he was hardly about to disagree.

"Their proposal seems logical," said Shino. "Why? Because even if they are strictly hostile to us, an exchange still puts both sides ahead relative to those outside of our collective. Additionally, if we refuse the Sand, they might use their knowledge of this meeting against us. Cooperation seems strictly optimal."

"I don't care," said Tenten. "I don't trust them." She was still holding her giant crossbow. She had never stopped aiming it at Kankuro's chest.

"I agree with Lady Hinata and Tenten," said Neji. "Trusting these foreigners seems foolish."

Sakura gave a small nod towards Sasuke.

"All right," said Sasuke. He turned towards the Sand ninjas. "In that case…"

"Hold on," Naruto protested, "this whole meeting was my idea. Don't I get a say in things?"

"Fair enough," said Sasuke. "What do you think?"

"Uhm," said Naruto, realizing that he now had to come up with an opinion. "I mean, I kinda agree with Hinata-chan that the whole thing seems... weird. But if they really do wanna work with us, it could be a very good thing. Uhm, meaning the benefits outweighs the risk, as long as we don't reveal our biggest weaknesses to them or anything." He absolutely had to get his hands on that puppet technique, and so did the rest of the group, whether they knew it or not. Besides which, this could be a once in a lifetime opportunity to try and mend the mistakes of the past and maybe even prevent a war in the future.

How had Jiraiya put it again? "One day we'll take on all the darkness in the world, kiddo, you and me, but right now this world just isn't fair at all…"

And of course, the Fourth's dream had been exactly the same once, ever so long ago.

Sasuke nodded slowly. "In that case, I'll add my vote to Naruto's. You two are welcome to take part in our jutsu exchange as long as the trade is fair. However, if either of my Hyūga friends notice you doing anything untoward…"

"You'll pluck out our eyes and feed us to the jackals," Temari said, waving him away. "I know, we do the same thing back home."

"Uh," said Kankuro, "I don't think they have jackals in the Land of Fire, sis."

Naruto was swiftly coming to regret his decision.

"So really all you have to do is infuse the seal on your palm the same way you would an explosive tag," Naruto explained. "As long as you got the right, uh, explosive mindset while you're doing it, you basically end up creating explosion-release chakra. The only downside is that, well, you have to tattoo a high-end explosive onto your hand with indelible chakra ink which goes off if you think about it too hard."

Tenten was staring at him with an unreadable expression, and Naruto shuffled awkwardly on the floor as he awaited the moment that she would yell at him for being an idiot. Instead, however, she merely looked back at the seal on Naruto's hand. "And I could use this to imbue my throwing weapons?"

"That's the idea," he said. "But, without shadow clones it'd be kinda hard to do so, since you don't really wanna buy chakra-forged weapons only to have them explode on first use." He glanced towards Shino, who was sitting next to him on the floor of the modest prayer room that the four of them had retreated to while his clone and the others dealt with the Sand siblings. "It would actually be much more useful for you, Shino, since you could transfer the explosive chakra to your bugs and detonate them while they're near your enemies. But since you're not a seal user, I guess it's a moot point."

That was the problem with transferring Naruto's best techniques to his classmates: They were all designed to work for him, and the whole thing kind of fell apart the moment one of the necessary pieces turned out to be missing. He wondered if Tenten was as disappointed as he would be in her place.

"It is just as well," said Shino. "The reason being, my insects are already able to carry explosive tags to their target if necessary." He adjusted his glasses, which gleamed darkly in the shimmering torchlight. "Additionally, it would be preferable if they possessed a method of attack which was less self-destructive."

"Uh, yeah," said Naruto. Shino still creeped him out somehow, even when he was not covered in bugs. "I was actually thinking that your greatest strength is your ability to exchange chakra between yourself, your bugs and your target. You're pretty much the only one of us who has a reliable way to store chakra, since chakra tends to resist being sealed." He shot a nervous glance towards the only door to their room. Temari and Kankuro were not supposed to have any sensing techniques, and Hinata and Neji had their eyes on them regardless, but you never knew with ninjas. "In fact, I have been working on a technique which I think might be perfect for you, but you'd only be able to use it once." He drew a scroll from his pouch and unsealed its contents, revealing an ornate three-pronged dagger within.

Tenten let out a small gasp, and even Rock Lee perked up at the sight of the old heirloom. "Is that…"

"Don't tell anyone," he said hurriedly. "Nobody is supposed to know I have this." He unfurled the parchment which he had wrapped around the handle of the knife. "This is a summoning scroll, the kind we were given in the Forest of Death. The basic idea is that you fill the knife with chakra, clone it, and then when the cloned knife hits your target the resulting burst of chakra activates the scroll and summons you to its location." He showed the scroll to Shino. "The thing is, I tested it and the natural resistance that makes it so difficult to seal chakra also makes it much harder to summon it, at least when it comes to people rather than spirit animals, since those kinda have to be able to absorb natural chakra just to stay alive. So if you're able to shunt all your chakra elsewhere, even temporarily, it suddenly becomes possible to teleport yourself without it costing everything you have."

Shino examined the scroll, his hooded face refusing to give the slightest indication of what he thought. "In other words, you would have my allies temporarily absorb my chakra and then carry this scroll in their pincers so they can summon me to their location before transferring the chakra back to me."

"Yeah," said Naruto. "Though like I said, since you aren't able to make more of these it's something you can only use once. In case of, you know – a bad situation." He became aware that Tenten was staring at the scroll with a distinctly hungry look in her eyes, and he instantly felt guilty again.

"This doesn't mean I have nothing to offer you though," he hurriedly said to Tenten. "You're a weapons expert as well as a seals mistress, so the best way to combine that would be to get you a seal-based weapon like that fan Temari uses. I was thinking I could assign one of my shadow clones to teach you light-release and show you some of the sealing tricks Jiraiya has taught me, and then maybe we could badger Sasuke to lend us some money so we can build you a chakra weapon of your own."

"A seals mistress," she repeated hollowly. She kept staring at the tattoos on Naruto's hands, only to look back at her own empty palms. "You know, I used to go into the forest surrounding the training glades every morning, searching for any unused explosive tags that the older ninjas might have left lying around. My parents kept telling me it was too dangerous, saying they would find me a teacher so I could make my own, but they could never afford to hire them for more than a few hours at a time." Her hands scrounged up, her fingers clasping the folds of her plain green trousers. "Why? Why are you…"

Lee clasped a hand on her shoulder and smiled brightly. "It is only natural that friends should help each other, is it not? After all, you helped Naruto-san during his fight against Gaara by letting him use that water scroll." He shot Naruto a look of purest gratitude, with only the tiniest hint of jealousy mixed in. He really did not seem to mind having to sit there and listen to the rest of them very much at all.

"I don't think you quite get it," Naruto said carefully. "I'd be teaching you how to use seals too, Lee."

Lee's face remained perfectly fixed. "Perhaps it is the case that nobody ever told you, Naruto-san, but my coils are incapable of moulding chakra effectively. I am unable to use ninjutsu or genjutsu of any kind."

"No you're not," said Naruto. "You're only unable to project chakra outside your body, but you can use chakra to boost your muscles just fine. If you're able to walk on water you can mould enough chakra to activate a seal which is tattooed into your own hands and feet." Even Inari had managed to use an explosive tag back in the Land of Waves, and he had been a civilian. Naruto flinched only briefly at the thought. "Tenten will infuse the storage seals for you each morning and fill them up with water and whatever else we can come up with, and you'll use them to create platforms to change direction in mid-air and unleash seal-encrusted indestructible projectiles while moving at your Eight-Gates boosted top speed." He looked him in the eyes. "Like you said, it's only natural that friends should help each other."

Slowly, Lee's hand dropped from Tenten's shoulder.

"It took me some time to figure out how your fan works," Naruto said, trying to contain his excitement and failing. "At first I thought it was the seals that you obscured with those purple sun markings, but if that were the case you wouldn't really need to swing the fan at all. So then I thought to myself, what is it that makes wind different from other elements like earth and water? And that's when I realized that wind is motion, and so even though you can save chakra by using an existing source of earth or water you still need to expend energy to make it move towards the enemy, but with wind you only need to start the effect and then you can simply amplify it with ninjutsu in a way that directly feeds upon itself."

Temari stared at him and said nothing.

"Uh, right. I guess you want me to get to the technique sharing part." Naruto shifted uncomfortably upon his tatami mat, shooting occasional furtive glances to the others, none of whom looked about to spring to his aid. He definitely could not bring up Gaara's death, but he also could not not apologize for it, which made it one of those unwinnable situations he somehow kept seeming to get himself into. "The most obvious way to boost your wind scythe technique would be to seal compressed air or maybe even poison gas into your fan like Tenten did with her water scroll, but I'm guessing since you even inscribed the summoning seal onto your fan you already thought of that one."

She was still looking at him with those unyielding teal eyes of hers. She still said nothing.

He swallowed thickly. "Speaking of which, I've been thinking lately about a way to summon even, uhm, people. It would actually make things a lot easier if you guys had access to a technique or a drug or something which could be used to temporarily suppress your chakra."

Kankuro exchanged a glance with his older sister. "I think elder Chiyo might have something like that."

"Great," said Naruto, relieved. "Then if I teach you my people summoning technique, in exchange, do you think you could teach us that puppet technique of yours? I, uh, think it could be really useful to us."

"Hey, hold on a moment," said Kankuro, raising his hands in a warding gesture. "Sharing our knowledge is great and all, but the puppet technique is the Hidden Sand's pride and joy. Lady Chiyo would literally kill me if I taught you that. And I know I said all that stuff about the Kazekage's children being untouchable, but uh, rules and logic don't apply to Lady Chiyo. Trust me on this one."

Naruto deflated. "Okay, well… what if you just taught us the chakra strings part of the technique? It's nowhere near as useful without being able to project the puppet technique through it, but I saw how you used it to deflect incoming kunai and pick up stuff while fighting Tenten and that could still come in handy." Naruto did his best to keep his breathing steady, fearing the moment that one of them would pick up on the rapid beating in his chest, but fortunately he already had an excuse to be nervous.

Kankuro exchanged another look with Temari. "Well… I mean, I guess there isn't much harm in that. You need some pretty intense chakra control to learn the technique, though. There's a reason why puppet masters are usually medical ninjas as well, in addition to being sealing masters, expert craftsmen and hidden weapon specialists." He said that last bit with more than just a hint of pride.

"The Gentle Fist is also known to require a great deal of chakra control," Hinata said. "Brother Neji and I could most likely learn this technique as well, I think."

The older Hyūga looked unconvinced. "Is this really going to make us stronger, Uzumaki? The Hyūga became the Leaf's greatest clan through our specialization in the Gentle Fist, not by learning how to more efficiently rearrange nearby household objects."

"I'm sure Sasuke will explain the finer applications of noncombat techniques to you later," Naruto shot back. He was not sure why he was even taking the time to help those two: It was pretty clear that their abilities would only end up being used to Sasuke's benefit, anyway.

Naruto chanced a glance at the Uchiha heir, who was leaning against one of the main hall's painted walls a short distance away from the rest of them. He had a far off look in his eyes, as if he had more important things to think about than a secret ninjutsu exchange between hostile ninjas from competing nations taking place right before his eyes, though Naruto was not sure how that was even possible.

"What about you, Sakura?" He extended her a hopeful glance, willing her to understand the true implications of a technique that could be used to project other techniques. "A medical ninja with perfect chakra control like you could definitely learn to use something like this."

She frowned, though he could not tell whether it was in consideration of Naruto's words or if she was thinking about the technique itself. "I suppose. It's at least something that might be of some use in the hospital, rather than yet another way to kill people or blow things up."

Naruto smiled at her in a way that was probably not really all that suspicious at all.

"All right," said Kankuro, eagerly leaning forward. "Here's the idea: You know how chakra dissipates over time to become part of nature, and that's why techniques all have a limited effective range? Well, the chakra strings technique works around that by basically looping your chakra together in a chain. Each link in the chain is like a separate technique, and so even though each part of the technique still has a limited range it all adds up to something amazing when you take them all together."

Naruto and Temari watched as Kankuro produced a chakra-forged chain from a scroll to illustrate the concept, and one by one the genin and even Sakura were drawn into the Puppet Master's training exercise. Sakura naturally had the most success channelling her chakra through the metal chain, and she even beamed a little at the praise she got from the others, her earlier reluctance momentarily forgotten.

"This was all his idea, you know," Temari said after a while. "Following you to this meeting, trying to spy on you, exchanging ideas with you and learning your techniques. I thought it was all a waste of time."

Naruto frowned, trying to make sense of the strange girl in front of him. "Then why did you come?"

"I don't know," she said. "I was just walking down the street when I felt this sudden urge to find out what you were doing. I suppose I wanted to look the man who killed my baby brother in the eye – to see what kind of person it was that could kill the little boy who I always had to stop from hurting others, but never had to stop from being hurt. I wanted to find out if I could look at such a person without blinking."

Naruto swallowed. "And what did you see?"

She turned to regard him, her teal eyes as unreadable as ever. "Nothing much."