"Mori, final safety check."

Kei took a long breath. She hadn't gone this deep in a while, not since before Shikigami-sensei killed Sumie-sensei and ended the future she thought she was going to have. In the future-as-planned, she wouldn't have been drawing on her Bloodline Limit like this until she was a lot stronger, both as a ninja and as a Mori. But Inoue-sensei had been emphatic. When experimenting with ninjutsu, there was no level of caution too high.

So she reached down, past the shadows that were the legacy of the Mori Clan's distant progenitors, into the depths of the Frozen Skein. She touched the focus point.

Thoughts, feelings, even the outside world—all was instantly washed away by a pale wave of apathy, its waters freezing into unbreakable ice that numbed all sensation. All that was left was the Mori Voice, the incurable poison in her bloodline's chalice.

Rest. Sleep. Embrace the nothingness within you. Will is struggle. Will is suffering. Step aside from the world, and know peace. Let the gears of fate grind without you. Forsake the agony of choice, the crushing responsibility of action, and find the happiness of pure oblivion.

The litany kept going, endless variations on a theme, the force of sheer repetition increasingly hypnotic, compelling. The Mori Voice was why you never, ever, went this deep without your defences in place.

But Kei's defences were ready. The counter to the Mori Voice was strength of purpose, and her purpose had been given to her by Inoue-sensei herself.

Final safety check. Three words repeated over and over like a mantra, one looping voice cancelling out another.

She drew the ice of apathy further up her body, past the frozen heart and into the structure of her mind. Final safety check. The words were a mould, reshaping the ice as it passed through them. Finally, the ice arrived inside her eyes, twin razor-sharp shards serving as lenses of dispassionate, merciless clarity.

Once those three seconds were over, Kei opened her eyes. She slowly scanned the clearing, from right to left.

Safety Rock A, out at the very edge.

The boar bristles in the centre, placed in a small pool of water. Wakahisa next to them. Safety Rock D next to both.

Kurosawa, on a treetop mirroring her own position on the far side of the clearing. Safety Rock B on the ground, some way past Kurosawa.

Inoue-sensei, lined up in a straight line with Safety Rock A and Wakahisa, hands in Substitution Technique position, medical kit and kunai both on her, within instant reach. Flawless.

Behind Kei herself, Safety Rock C, out near the edge of her range.

All relevant objects were in position, including Kurosawa, Wakahisa, and Inoue-sensei. The next step was to draw the overlay of causal webs between them, and simulate their interactions given the various possible failure modes of the experiment. Were there any variables she had not yet taken into account?

Finally, Kei concluded that the precautions taken were an acceptable balance of probability of injury or death versus available time and material resources, and that further optimisation would be impractical.

The task complete, Kei took a few seconds to melt back into her normal self.

"Safety check OK. Wakahisa, you may go ahead."

o-o-o-o

"In other words," Hazō summed up, "we've got nothing."

"Hey, I tried, OK?!" Wakahisa reacted. "But I'm not a sensory type. I never said I was. For all I know, those bristles are bursting with top-quality Wakahisa Noburi chakra right now, only a certain genius came up with this experiment without figuring out how to measure the results."

"Come on, kids," Inoue-sensei said in a placating voice that almost managed not to be condescending. "A negative result is still a result. And honestly, part of me is a little relieved nothing happened. I had these visions of Noburi commanding a legion of undead steelbacks, and there's no way that was going to end well for anyone.

"Now the fact that you couldn't sense, never mind drain, the chakra that was already there—that was more of a surprise. Isn't sensing and draining chakra through water a big part of the Wakahisa package?"

Wakahisa squirmed. "The mechanics of how it works are a clan secret. I shouldn't talk about it."

Inoue-sensei fixed him with a long, thoughtful look.

"Noburi, I'm not a clan ninja. My mother was a civilian, and my father was a mystery I never cared to solve. So I realise I don't know what it's like for you. Maybe giving away clan secrets is the ultimate dishonour for you, something that would weigh you down for the rest of your life. And if that's what you tell me, I'll respect it.

"But there is one thing I do know. The three of you, all Bloodline Limit kids, are incredible assets."

She paused briefly.

"I mean you have incredible assets. Jeez, I sounded like one of those soulless pencil-pushers in the Mizukage's Office for a second. Anyway, those Bloodline Limits? They're your ace in the hole, the one thing you have that even jōnin don't, at least unless they're from your clan. And as a group, they're something we have that no other missing-nin do.

"As I say, I'm cool with however you choose to deal with the clan secrets thing. Just be aware that what you tell the rest of us, and what you don't, could make a very real difference to our odds of survival."

To his credit, Wakahisa managed to hold his ground for entire seconds.

"All right. So the thing is, using my Bloodline Limit is like making myself a channel between the chakra in the water outside and the chakra in the water in my supply, with the water in my body as a medium and a filter. Sensing chakra in the water is part of that. So if I can't sense chakra even when it's in the water, then that's probably because I can't channel it for some reason."

"I have a theory," Mori cut in. "The blacksmith thought the chakra in those bristles was probably Earth Element. But the chakra in Wakahisa's canister is completely neutral. Maybe his Bloodline Limit just doesn't work on elemental chakra?"

Inoue-sensei nodded. "Something to think about."

"Hold on!" Wakahisa exclaimed. "Don't write me off just yet! There was the thing with the water clone!"

Hazō looked at him blankly. "The thing where you tried to drain it and it burst apart and nothing happened?"

"Yes! I mean no! I mean I felt something! If I can't absorb elemental chakra, then I guess that goes for my own elemental chakra as well, but… I got the feeling that maybe, if I was faster or more focused or whatever, I could've held onto the clone's Water chakra long enough to recycle it into some other technique!"

Inoue-sensei shrugged. "That's an experiment for another time, I think. We need to make good use of the next few days for training, before the caravan arrives. And hey, we experimented with Bloodline Limit ninjutsu and no one got killed, maimed or even particularly humiliated. I call that a win!"

o-o-o-o

The caravan, when it finally came, was impressive. There were three wagons, pulled by things that might have been cows if they'd had the right number of legs and didn't have greyish-blue carapaces and permanent expressions of thoughtful ennui. There were also, as far as Hazō could see, three guards: a giant of a man with a somewhat clichéd huge club over his shoulder, a young woman with a shortbow on her back, and an older woman with a sword at her hip, in a proper scabbard, no less.

"Yamada, huh? You can call me Baikan, trader at large!" the middle-aged man in the front wagon exclaimed with a sweeping, dramatic hand movement, followed by a self-deprecating chuckle. "My wife Miyu's in the back, sorting out the inventory. What're you interested in, Yamada? A nice heavy coat for the winter? Not that it's ever anything but winter up here, but it's the thought that counts. Or maybe some spices? If you're anything like me, you need all the help you can get making your cooking taste like there was some actual food somewhere in its ancestry. Or maybe you need to impress a lady friend? I've got all sorts, from –"

"Uh, Mr Baikan, sir, where is your caravan going from here?" Hazō interrupted.

"We've got ourselves a neat little route along the coast, lad. We swing through Rice, then spend a little longer than might be strictly necessary in Hot Springs," Baikan gave Hazō a wink, "make our way across Frost—quite the contrast, let me tell you—and then we either press on into Lightning or double back, depending on how trade's going. Why do you ask? You thinking of joining us?"

Hazō gave what he hoped was a noncommittal shrug.

Baikan waved the younger of his female guards over. "What do you reckon, Aya? Does he strike you as the sort of lad who could keep us safe out on the road? Can't have too many hands on deck, not after the ghost moth incident."

Aya studied Hazō's figure and body language carefully. Hazō did his best to stand like someone who could handle himself in a fight, while not being a member of an elite warrior caste individually capable of wiping entire armies off the face of the earth (eventually, anyway).

After a couple of seconds, she shrugged. "Seems all right to me. Long as he keeps his hands to himself, I've got no problem with it."

Baikan gave a satisfied nod.

"There you go. No need to rush into anything, mind. We'll be spending a few days here, trading and resting and whatnot. I should probably look for new investors, too, after what happened to poor Kanda, but given how there's less than a hundred people in this village, I'm not too optimistic."