Doing something a little different today. This chapter was written by both myself (@eaglejarl) and @Velorien in collaboration. Enjoy!​

It should have been a dark and stormy night. The clouds should have been crackling with ominous thunder. The darkness should have been pressing in like an animate, oppressive force. The sounds of animals moving around should have been taking on an eerie, sinister edge, and Hazō should have been feeling an inexplicable desire to speak in no more than a hushed whisper lest he draw the attention of something terrible.

"Who wants another squirrel on a stick?" asked Jiraiya.

"Ooh, ooh, me!" Noburi said, doing the next best thing to snatching the stick from Jiraiya's hand before dunking it in the Akimichi teriyaki sauce that Kagome had grumpily authorized eating, solely because he'd provided the ingredients and then watched the cooks prepare it. (The Akimichi had started off amused and happy to satisfy the request of their Hokage. They hadn't ended that way.)

It was that kind of night and Noburi was hogging the squirrels. This was not what Hazō had signed up for. (Not that he'd signed up for anything, as that would imply Mari-sensei giving any of them a choice.)

Keiko sighed. "Far be it from me to reject the joy of partaking in incinerated rodent, but I do believe we had a purpose in coming here."

"Yes!" Hazō exclaimed. "Mari-sensei, you promised us, and I quote, 'an unforgettable family bonding experience through shared horror over what half of us do with our spare time'." With a move memorised to perfection over the course of the evening, he grabbed the next squirrel before Noburi could react. "And not that the things this teriyaki sauce is doing to my tongue aren't horrifying, but I did assume you were referring to the tales of sealing failures Jiraiya's been hinting at all this time."

"Sealing failures, huh?" Jiraiya said thoughtfully. "Seems a little dark. It's a nice night, can't we just enjoy each other's company?"

"Hmph," Kagome said. "Like you've got any stories about sealing failures, Mr. 'Oh-I'm-the-Greatest-Sealmaster-Ever-and-So-I-Don't-Need-Precautions'."

"Kagome," Jiraiya said patiently. "How do you think I became the world's greatest sealmaster? Everyone starts off ignorant, I just survived long enough and learned enough to be the best." He preened a bit. "Of course, being incredibly gifted helped a bit."

"Hmph."

Jiraiya rolled his eyes. "Fine," he said, "let me tell you about the kind of people I worked with back when I was studying in Leaf's sealcrafting facilities—the world's best, mind you, staffed with the elite of the elite. Our janitors knew more about sealcrafting than some of the experts in the other villages." Kagome gave another "hmph", but Jiraiya ignored him.

"The elite of the elite," he repeated. "And if you wanted to live long enough to get promoted, you had to pay attention to every tiniest detail of what they told you. For example..."

Jiraiya shifted into a more comfortable sitting position.

"When I was a new recruit still getting my feet wet," he began, "I was taken on the standard tour of the Hall of Candles. They showed us each sealmaster's candle and the inscription underneath it—their name, their date of death, what they'd done wrong and what happened to them as a result. Your typical apprentice couldn't sleep for a week straight after that, longer if they had a good imagination. Put you in the right frame of mind.

"But there was one candle which only had a name: Ishimura Junior. He was in the Hall of Candles, but he wasn't dead.

"I recognised the name, of course—the Ishimura Junior reports are required reading when you're inducted, because the man has a ton to say about protective barriers and layered defences. So I asked.

"What they said is this: Nobody knows when Ishimura Junior died. Nobody knows if Ishimura Junior died. Nobody knows if he ever lived. The people who would have been his colleagues don't remember ever meeting him. His signature on those dozen reports is all there is.

"And you know how the last of his reports ends? 'My next safety feature should make sure nobody ever suffers the same fate as', and the rest of the line is blank."

Hazō shuddered. "Did they ever figure out what the safety feature was supposed to be?"

"No idea," Jiraiya said. "We don't even know what it was meant to prevent, not really, or how common that thing is. Think about it: everyone knows about Ishimura Junior because, if he ever existed, he was really good at what he did, and his reports get used in training every year. How many other reports might there be filed away that nobody ever sees? How many of them have signatures nobody would recognise? How many don't?

"This is the thing some sealmasters"—Jiraiya eyed Kagome briefly but meaningfully—"can't get their heads around. The worst sealing failures aren't the ones where people get flayed alive and then their skin put back on inside out. It's the ones where you don't know what happened—or how to stop it happening again."

"Are you implying that specific types of sealing failure are preventable?" Keiko frowned.

Jiraiya shook his head. "Not the failures. But sometimes, knowing exactly what happened during a sealing failure is the only way to save yourself from its consequences.

"There was this one time when I was on a diplomatic mission to Hidden Rock for Sensei. They wanted to show how powerful they were and what good allies they could be, so they took me through their sealing labs...."

o-o-o-o​

The door swung open on well-oiled hinges. Somehow, Jiraiya could almost hear the creeeeeeak that should have been there.

"And this is Room 112," said Imai Kenzō proudly.

Jiraiya looked inside without moving any closer to the door. The room was tiny, barely the size of a large closet, and completely empty except for a chair that faced the door, a desk in front of the chair, and a trio of inkstones placed haphazardly across the desk's surface.

"It's empty...?"

"Yes," Imai said, nodding sagely. "I check at least once a fortnight, more often after we lose someone."

Jiraiya waited, but the Hidden Rock sealmaster just stood there. "Why?" the Sannin finally asked, knowing full well that it was a straight line.

"To make sure there's always someone alive who remembers that Room 112 is empty." He smiled. "Preferably someone who doesn't live here in Hidden Rock."

o-o-o-o​

"Pfffft!" Kagome pffted. "That's the best you've got? Let me tell you what a real sealing failure looks like....

o-o-o-o​

The other students laughed at Kagome when he came to class in a smock, balaclava, and gloves that overlapped his long sleeves. The first time a proctor, Sugawara Dan, exploded and soaked them all in blood and brain matter they glared at his smug expression but continued to wear their normal attire. The second time it happened everyone took turns quietly asking him for recommendations on which fabrics were the most bloodproof.

The third proctor, Murata Chōei, didn't explode. He shredded. Half of his body mass vanished...not half of his body, half of his mass. Strips of flesh and bone from random locations simply winked out of existence, leaving him a screaming, oozing mass of agony on the floor.

Murata didn't die. The blood flow stopped in less than a minute as some of the strips reappeared. They didn't reappear in exactly the same places, leaving small cracks in the skin and upthrust ridges where the flesh now overlapped. Over the course of a week the cracks filled in with teeth and eyes. No one seemed to notice and they certainly didn't believe Kagome when he pointed it out.

o-o-o-o​

"Ouch," Jiraiya said. "Yeah, I always hated the Type 7-G incidents. Of course, sometimes you get something simpler, like that one time that Noguchi's digestive system got reversed. A liquid diet proved to be best after that, since it tasted least bad on the way out. Poor guy lived six months like that."

"Yeah, well, we had someone live for a year after being turned inside out," Kagome said immediately. "It was gross. You could see his brain beating, and he left bloody footprints everywhere."

Noburi frowned. "Brains don't beat, Kagome," he said. "Hearts beat."

"Were you there, Mr.-I'm-So-Stinking-Clever? No, you weren't, so you just shut up."

Noburi shrugged and chewed thoughtfully on his squirrel. "That would actually be really cool," he said after a moment. "Do you remember what the blood system looked like? Dr. Yakushi has been speculating on whether it's a set of loops or a static pool."

Kagome glared at him and masticated a defenseless squirrel-kebab to death.

"Tsunade believes it's a single closed loop," Jiraiya offered. "She's generally right about that sort of thing since, y'know, world's best medic-nin." He smiled. "Just like I'm the best sealmaster. Because Legendary Three."

"What about Orochimaru, Jiraiya?" Mari-sensei asked. "What was he best at? You mentioned once that he liked to cut things open and that you were making seals for him—did anything ever come of that?"

Jiraiya shuddered. "Nope. Nothing."

She raised an eyebrow. "Nothing?"

"Nothing."

"And they say I'm a bad liar," Kagome grumbled. "Reminds me of this one time...."

o-o-o-o​

"You are an idiot who should not be allowed near an inkbrush, much less a testing lab," Kubo said. "Also, I'm very embarrassed about saying that and I hope I don't get in trouble for it. Secondarily, you are smoking hot and I want you to drag me to bed by my hair so that you can tie me down and make me lick every inch of your body."

"What?!" Otsuka shrieked, leaping to her feet.

Kagome started shoveling his food down so he could get away before things really went south. These conversations never went well, since people didn't like it when you were honest with them. Worse, Kubo's conversations frequently devolved into violence that involved collateral damage to everyone else in the lunchroom.

"Now I'm really embarrassed," Kubo said, blushing furiously. "I hate saying those things to you, but I really don't want the broccoli getting into my eye."

It wasn't actually broccoli, of course, but the growths did look remarkably broccoli-esque. New ones sprouted every time Kubo kept a thought bottled up, and they seemed to be evolving. The one on his nose had grown claws last week and was ever-so-slowly growing towards his left eye, the claws clacking furiously as it grew. Worse, the clacking was starting to sound like words.

o-o-o-o​

"Semi-sapient growths on the face, huh?" Jiraiya said. "Yeah, that's bad. Could be worse, though.

"I remember when Murabe, one of the other guys in my division, called me over to help him set up for a trial. Luckily for me, I was late because I got stuck in an argument between Yuri and Mikako over who got to jump my bones—this was while I was still young and stupid, you understand, and didn't realise it was a false dilemma. By the time I got to Murabe, it was all over.

"The best way to describe what happened to Murabe was... 'out of phase'. He wasn't all there—not mentally, but physically. You could sort of see through him if you squinted hard enough, and while he was all right while he was concentrating, the second he got distracted he started moving through things. Trouble was, things started moving through him too. He got real sick real fast, and it took us time to figure out that this was because the air was getting past his skin and rubbing against his insides. He wasn't completely out of phase, you see, just a bit. He got prescribed complete bed rest, because he was mostly fine as long as he didn't move at all and was indoors where there was no wind.

"But what happened to him was nothing. Here's the really weird thing. He hadn't been testing a seal.

"Murabe was a smart guy, one of the best I'd ever worked with, and he knew better than to forge ahead with a risky experiment just because his helper wasn't there. He was still in the process of double-checking his calculations when whatever happened... happened.

"Now the idea of getting hit by somebody else's sealing failure out of nowhere is scary enough. But it gets worse. Murabe was an early riser, and he was the first to set up for an experiment that day. There was nothing in the facility that could have triggered at that time. In other words, he got messed up by a sealing failure when no seal had failed.

"And then it's a month later. To the day, actually. I remember because Yuri made a big deal out of the anniversary. Mensiversary. Whatever. There I am, in the testing area where Murabe had his accident, minding my own business with a Banshee Slayer prototype, when suddenly the man himself staggers in. Bear in mind, he's not suicidal. He's been starting to fade back into phase, meaning there's hope for a complete recovery—as long as he doesn't do what he's doing right now.

He looks terrible. He's panting, and his eyes are bloodshot. You can sort of see inside him, only instead of organs or what have you, it's all red with blood, like he was tearing himself apart against the air in order to get here.

"He walks up to me, grunting with every step. 'Jiraiya,' he says, 'where's my prototype sonic catalyser seal?"

"I tell him I'm damned if I know. It's the early hours of the morning and I'm barely awake. I'm not going to remember where his stuff from a month ago got stowed after the medic-nin were done with him.

"He looks me in the eye, and he's got the look of a desperate man. 'Jiraiya, if you don't get that seal here in one hour, I think the world will end.' And then he falls to his knees, struggling to breathe.

"Well, what was I going to do? Murabe wasn't one for drama, and he was wrangling seals while I was still beating up bullies at the Academy. I run for the storerooms like all our lives depend on it.

"Fifteen minutes later, I get back with the seal, and he's in bad shape. Coming out here cost him big-time. He's leaning against the wall like it's the only thing keeping him up, and I wouldn't be surprised if he keeled over any minute. So I hand him the seal that he never got to infuse the first time round. 'What's the deal, Murabe?' I finally ask.

"'I have to make sure this seal fails,' Murabe wheezes. 'By the Sage of Six Paths and all his disciples, it has to fail.'

"And before I can lift a hand to stop him, he infuses the seal. I dive for cover—

"And nothing happens, except he collapses to the ground again. It didn't take a medic-nin to tell that the stress had been too much for him. He'd given his life to fail an infusion, but the failure didn't do anything."

"Bird poop!" Kagome said. "No such thing as a sealing failure that doesn't eat your face in horrible, horrible ways. Or make broccoli grow out of it."

"I was confused too. At first, I thought he must have infused the seal successfully after all. Which is crazy. How do you fail to fail an infusion? And then I realised... it had done something after all. It just hadn't done it now."

Silence fell as the family digested that.

"I had no idea sealing failures were so dangerous," Mari-sensei said. "I've watched these two for a year now. I've seen explosions, portals that create blade monsters, chakra constructs that look like talking porcupines, and all kinds of crazy stuff. I've never seen the kinds of things you're talking about."

Jiraiya shrugged and took a pull on the canteen of sake at his feet. "From what I can tell, Hazō has mostly been working on variations of storage seals, which are the second best-understood seal in existence. They're an extremely stable design that's very hard to get wrong, which is why they get taught to novices.

"Kagome," he said, turning to his colleague, "I may not agree that all of your precautions are necessary, but the fact is that you're good at what you do. Adding a chakra adhesion trigger to the air domes was a clever bit of jiggery-pokery, and the implosion seals are a cool variant on storage."

He looked back to Mari-sensei. "Point is, Hazō has been dealing with stuff that's hard to screw up, so it's not surprising that most of the screw-ups have been fairly tame. Once you start getting into more esoteric research that isn't the case anymore."

He paused, staring meditatively into the fire and sipping on his canteen. When he spoke again his voice was quiet, his thoughts clearly far away.

"There were two prodigy twins at one of our facilities: Ikaruga Yūji and Ikaruga Yūhei. They always worked together. Co-authored all their papers, collaborated on every project. Rumour had it that they were even dating a pair of sisters. And one day, while doing some extremely esoteric and very classified research, they got hit by the same sealing failure.

"At first it seemed like nothing was wrong. For a second, they just stood there. But then Yūhei clutched his head as if it was about to burst apart, screamed to the heavens and collapsed on the spot. And Yūji just gave this creepy little smile and said, 'Well, that's never happened before'.

"Yūhei didn't wake up after that. He was in a coma. They left him in the sealmasters' dormitory to keep an eye on him in case there were more effects, and made sure Yūji stuck around until he got a clean bill of health from the medic-nin. Yūji seemed fine, though. He walked around, talked to people, studied sealcrafting notes and reports like any normal sealmaster—only he never stopped wearing that creepy little smile.

"All normal, until the day he deliberately triggered a sealing failure. By the time they were done with the evacuation, he'd disappeared, and nobody ever saw him again. Everyone assumed he'd decided to turn missing-nin, though there was no clue why.

"Two days later, Yūhei woke up. His colleagues were all relieved to find him in good health... until he opened his mouth. Nothing he said made sense, and eventually everyone gave up on listening to him and just treated him as another traumatized sealmaster."

"What kind of things did he say?" Hazō asked.

"Oh, a whole bunch of crazy stuff. I can still remember a little of it.

'There isn't enough blood in the children.'

'It's so cold here, inside the others.'

'They will obey. Once they've looked into the sun, they will obey.'

'Too many hands. Why are there always too many hands?'

'I have run out of right angles. I must start again.'

"A week later, the news came in that the hunter-nin had tracked down Ikaruga Yūji. They wouldn't talk about how they found him or what they'd seen, but they reported that when they got there he'd already taken his own life. The same day, Yūhei spontaneously snapped out of his madness, and as far as anyone could tell it had no lasting effects... except that every now and again, people would see him smiling this creepy little smile."