Kagome-sensei smiled the beatific smile of an elder whose superior wisdom had finally been recognised by his wayward children—or possibly of someone savouring particularly good cake after months of field cooking, it was hard to tell.

The rest of the team were less sanguine.

“Kagome-sensei,” Hazō said anxiously, “this has serious implications. I need to know more.”

“And I need more cake,” Kagome-sensei retorted.

Mari-sensei obliged.

Truthfully, Hazō wished he had some way to communicate with her subtly, because she’d be much better at asking the obvious question without alarming Kagome-sensei. But given that the man was still right in front of them, he could see no way of doing so.

Hazō braced himself and plunged onwards, into the depths of horror. “How exactly do you know all this, Kagome-sensei? You mentioned access to ancient records, didn’t you? What are they, and how far back do they date?”

Kagome-sensei slammed the piece of cake he was holding back down onto the plate.

“Don’t ask that question! Never ask that question!

“Never,” he repeated more slowly, “much less in a place you’ve only got Jiraiya-stinker’s word is secure. Do you want Leaf’s secret police ripping the knowledge out of your mind so they can track down and destroy every piece of evidence that can expose their lies?

“Some of it’s passed down by word of mouth from sealmaster to sealmaster. Some of it comes from deeply sealed crypto records. Some of it comes from books and scrolls that would be better off never seeing the light of day. And some of it’s just plain common sense when you know what to look for. Truth is, I shouldn’t even be saying some of this stuff out loud, especially in Leaf, but you need to know.”

“And the dating?”

Kagome-sensei flinched. “A threat you managed to escape by the skin of your teeth. Don't let them draw you back in, or there'll be no saving you this time.”

Mari-sensei snorted.

“Oh, wait, you mean the records. There's no clear answer. The further back you go, the more you have to put the pieces together yourself. It’s lucky I know what to look for. Being a sealmaster’s all about spotting these patterns that the secret rulers of the world don’t want anyone to see.”

Hazō nodded. “Right. And those patterns include things like Whirlpool revenants? Could you tell us more about those?”

Kagome-sensei shuddered and went to pick up his cake. He spent a few seconds staring at the squashed lump he found on his plate, then passed it wordlessly to Mari-sensei for replacement.

“Well, the Sage wasn’t exactly going to let all that Whirlpool knowledge go to waste, was he? Instead, he decided to take advantage of the lupchanzen’s amazing memories. He took some of the older ones, stuck them in kids who were too young to have proper memories of their own, and gambled on them turning into bad copies of the people the lupchanzen remembered. Didn’t work out too well, obviously—the kids grew up half-crazy at best, bits of forbidden knowledge and memories that weren’t theirs floating around inside them, and lupchanzen doing things to their brains that even lupchanzen weren’t designed to do. Some of them escaped. Others killed themselves. The rest are still in Leaf, serving in Leaf’s secret police alongside other products of failed experiments.”

“What exactly happened in Whirlpool?” Hazō asked. “How did the information about their research get leaked, and why didn’t the Sage use all his power to protect them afterwards?”

“Isn’t it obvious?” Kagome-sensei asked. “It was because of Hidden Depths. They had a good deal going with Whirlpool—drowned anyone who got too close to Whirlpool’s offshore research facilities, the ones too dangerous to keep in Whirlpool proper, and in return the village gave them all these handy seals to make underwater life easier. Only that was before Depths found out about the lupchanzen.”

“How did they find out?”

“Haven’t you noticed the pattern yet?” Kagome-sensei demanded incredulously. “The Sage and Dummy are really crap at keeping their secret weapons under control. It was only going to be a matter of time before some lupchanz decided to make a break for it, especially with their powers, and where was it going to go except in the water?

“Obviously, Hidden Depths could see the writing on the wall. So they had their summoner tell the Kraken Clan, and the Kraken Clan leaked the info to some of the big village summons, and next thing you know, Whirlpool wakes up to an army on their doorstep.”

“Surely the Sage could have just flattened the army?”

Kagome-sensei shook his head. “The Sage is the ‘nice’ brother, remember? He’s not going to reveal himself and make a huge show of force that’ll turn all the other villages against him, just to protect an experiment that may or may not work out. No, he wrote it off as more evidence that sealmasters were unreliable and moved on. Mind you, we all assume that it was Whirlpool who took out all those soldiers, but it’s funny how that army disappearing was what both started the war and made sure Leaf had a huge advantage in it.”

“And what happened to the lupchanzen?” Hazō asked. “How did some of them end up working for the villages that destroyed their creators? Shouldn’t they all have flocked to Leaf, on their own or because the Sage reeled them back in?”

“The experiments weren’t finished, remember?” Kagome-sensei gave Hazō what he couldn’t help thinking of as a very Nara look. “The lupchanzen weren’t all as loyal as they were meant to be. And besides, even the Sage isn’t going to have an easy time tracking down lupchanzen. You remember what they are, right?”

“What about some of the other dangers?” an uncomfortable Hazō decided to shift the subject. “You’ve mentioned gaki before, haven’t you? And damnbeasts?”

“Good memory,” Kagome-sensei nodded approvingly. “The gaki are what happens when some young idiot sealmaster decides that they can perfectly well reverse-engineer their own summoning scroll instead of listening to their elders. Oops, instead of a gate to the Summon Realm you’ve got a gate to Hell. Suddenly, you’ve got gaki flooding in everywhere, because gaki are hunger spirits and the human world is full of tasty souls for them to eat. And that was lucky for us. At least the gate led to one of the other paths, and not, say, Out.”

“’Out’?” Mari-sensei asked. “Out where?”

“Not out where,” Hazō said firmly before Kagome-sensei could answer. “Just Out. And you don’t talk about what’s on the other end, because there are some things that, when you start paying attention to them, they start paying attention to you.”

“So let’s talk about gaki!” Kagome-sensei screeched at the top of his voice. “Fascinating things, gaki. Much more interesting than any old forbidden dimensions anyone might be wondering about. See, after a bunch of people got devoured, the sealmasters managed to seal the gate, but of course some bright sparks decided to keep a few gaki around, because having something that can eat souls is a great way to make sure people die when they are killed, if you know what I mean. Nobody knows the danger of immortals better than the Sage.”

“Kagome-sensei, does the existence of gaki prove that souls exist too?"

Kagome-sensei shrugged. “The gaki seem to think so, but then again they’re not all that bright. Me, I don’t know about any seals that interact with souls, so I don’t really care. Anyway, that’s gaki. The damnbeasts… well, they’re not really called damnbeasts. That's a stupid name. But bad things happen to people who go around using the real one. All I know is that they’re smarter than gaki, and gaki are scared shitless of them, and so is everyone who knows even a little about them. So naturally Leaf made a deal with them to keep the gaki under control in exchange for keeping them well-fed.”

“Leaf really are the bad guys here,” Hazō noted.

“Nah, they just have the most resources,” Kagome-sensei said. “It's not like Cloud or Mist don’t have enough skeletons in their closets—I mean, Mist is run by a Tailed Beast—but if I got into those, we’d be here all week.”

“What about the Tailed Beast Breeding Programme?” Hazō asked. “Only Leaf has one of those, right?”

“Had,” Kagome-sensei said. “After Dummy managed to split the Ten-Tails into nine weapons he could control more easily, he decided to try doing the same thing again, only now with human hosts involved. That was half the point of the lupchanzen project—make Tailed Beasts that a human can control, then make a tool to let you control the human. But of course Dummy screwed it up. Got the Fourth Hokage killed in the process, in a very messy and public way. The Sage was able to cover up exactly what happened, but it sure put a crimp in his plans to replace the Fourth now his Hiruzen persona was getting old."

“You said earlier that the gaki were an accident from summoning scroll research,” Hazō said. “What do you know about the actual Summon Realm? Why did the Sage make it, and why aren’t you allowed to use seals there?”

“You’re not allowed to use seals there?” Kagome asked. “Huh. Did not know that. Makes perfect sense, of course. Dummy made the prison ninjutsu-proof, but they both knew jack about sealing, so they had to make sure nobody could use it to try to escape.”

“The Summon Realm is a prison? A prison for whom?”

“The other sages, of course,” Kagome-sensei explained matter-of-factly.

“Couldn’t risk somebody figuring out how to unmake chakra, or making a stronger weapon than the Ten-Tails, or just plain beating the Sage and Dummy through superior firepower. So our boys struck first. Forced their rivals to use the old Transformation Technique to turn into chakra beasts, then stuck them in an artificial reality where nobody could find them and save them. Except since they knew what they were doing in advance, they let the sages become superior chakra beasts instead of mindless animals, as a sort of final mercy."

“Why didn’t he just kill them?” Mari-sensei asked. “You don’t take prisoners unless there’s something you want out of them.”

“Because he was even more of a bleeding heart then. And some of them had been his friends, back in the day. Might have even helped him invent chakra. I mean, does something that world-changing sound like one or two people’s work to you?

“So the Sage let them live out their lives as chakra beasts, and then went to their kids and said, ‘Hey, you guys want time out for good behaviour? Just sign these contracts and I’ll make it happen.’ And boom! Another immortal superweapon for the Sage. Not as powerful as the Tailed Beasts, but oh so much more flexible and obedient.”

"Then why doesn't Leaf possess all the summoning scrolls?"

“Remember how the Sage and Dummy kept fighting? They each gave the scrolls they had to their proxies. The scrolls ended up getting passed around over and over as some clans beat others, and eventually the diplomatic ties in both realms got so snarled up that the Sage couldn’t be bothered tracking down all the scrolls and subduing all the summons again, and gave it up as a failed experiment like the Tailed Beasts.”

Hazō nodded. “Can we backtrack a little? Do you know what chakra is? What was the world like before it existed?”

“Chakra is a parasite,” Kagome-sensei said. “A single completely interconnected artificial intelligence, using living things as hosts to grow and reproduce, and smart enough to do absolutely anything, except it’s got no initiative whatsoever.

“The Sage thought he could piggyback off its intelligence to make the chakra in one person talk to the chakra in another, make them understand each other on a gut level. But of course he screwed it up. It didn’t occur to him that connecting everyone wasn’t enough. Sending and receiving are active processes, and he'd made chakra passive.

“Ninjutsu was supposed to solve that. You create a language to give chakra orders, and then you order it to tell everyone what everyone else is feeling. But Dummy couldn’t hack it, and frankly he wasn’t that interested, because he’d just been handed the ultimate weapon. Why bother trying to make people understand each other, with no guarantee that it’ll even change how they behave, when you’ve just learned how to set people on fire with your brain?

“As for the world before chakra, it’s a mystery. I’d bet my left kidney—no, make that Jiraiya’s left kidney—that the Sage deliberately destroyed all the records he could. Wouldn’t want someone using ancient knowledge to reverse-engineer what he did. All I know is they spent a lot of time fighting, and if the Sage and Dummy are anything to go by, they had way better education than we do.

“I’m running out of cake.”

“Just a couple more questions, Kagome-sensei. If the Sage and Dummy didn’t know anything about sealcrafting, then where did it come from? Who were the first masters?”

“Good question,” Kagome-sensei said seriously. “I was going to wait to tell you once you’d graduated from your apprenticeship, but now you already know too much, so it’s a moot point. See, the Sage had kids—two brothers who decided they didn’t fancy living in a world where Daddy was absolute ruler for ever and ever. They were never going to beat the Sage and Dummy at their own game, so they came up with something else—something that anyone could use if they were smart enough, without having ancient lore coming out of their ears or making themselves into a chakra powerhouse.”

Kagome-sensei’s voice took on a ritual cadence. “A power earned not by birth but by dedication. A power that grows stronger with every wielder and every generation. A power founded on truth, to defy those who would keep the truth from us.”

“Sealcrafting,” Hazō breathed.

“Sealcrafting,” Kagome-sensei said proudly. “The Sage managed to erase their names from history, but he couldn’t wipe out sealcrafting, and after a few close calls with cornered sealmasters and undefined behaviour, he stopped trying. Instead, he created hidden villages where sealmasters would be under his control, or at least under the control of somebody he had influence over, and where there’d be plenty of oversight to stop them wrecking the world before he could save it.”

“Are you saying that hidden villages exist because of sealmasters?” Mari-sensei asked sceptically.

“Oh, they exist for lots of reasons,” Kagome-sensei waved away her question. “It’s just that this is the one that matters. And of course, gathering sealmasters into villages has only sped up our research. Isn’t it great when people’s plots come back to bite them in the ass?”

“This is… a lot to take in,” Hazō said dazedly. But it was too late to turn back. There’d be plenty of time to regain his lost sanity after this meeting… hopefully.

“What about Akatsuki?” he asked. “Who are they?”

“The greatest thorn in the Sage’s side,” Kagome-sensei said. “See, back in the days of yore, they were this group operating out of Rain. Bunch of dumb idealists. Only then they briefly got famous because some schmo wrote a book based on them. I read it myself. Cheap trash, but I guess the writer must have had a lot of pull, given how there were copies everywhere from Demon Country to the Kazekage's latrine.

“Thing is, the Sage didn’t like Akatsuki's flavour of pacifism. Close enough to his to appeal to the same target audience, different enough to be competition. And it just so happens that around that time, he had to find a place for Dummy who was turning everyone into clones. So he chucked one problem at the other.

“Only he didn’t figure on Hanzō of the Salamander. Hanzō was on Akatsuki’s side, and he gave up his life to save the leaders. Used his super poison skills to block Dummy’s cloning long enough for them to get out. Ever since then, Akatsuki have been these terrifying killer mercenaries, working for everyone under the sun except Leaf. They have no problem hiring missing-nin, and they control the underworld. The Sage has tried to crush them dozens of times, but they’re hidden, they’re mobile, they’re stinking rich, and even if you force them into a fair fight, they go through jōnin like rice crackers.”

“Best avoided, then,” Hazō said. “OK, there’s just one more question on my list.”

“Hazō…” Mari-sensei said meaningfully.

“Purely mental list, Mari-sensei!” Hazō said quickly. Lists that had been written down but then destroyed once he was done memorising them didn’t count, right?

He rushed on before Mari-sensei could query this.

“What about scorch squads? If the Sage is such a nice guy, why does he use them?”

“Dummy talked him into it. Leaf didn’t invent the scorch squads, but they couldn’t afford to let all their enemies beat them on demographics—the Sage’s a long-term thinker, remember. That alone might not have been enough, but they also had all those experiments they wanted to run, and they weren’t going to use their own civilians as subjects…”

Hazō felt sick. “I—I think that’s everything I wanted to know for now. Thank you, Kagome-sensei.”