(Still Gathering Artorium...)
"How're you two holding up?" Gudako asked the star pair of the Event (though it technically didn't actually pass the threshold for the classification). "I know you don't need sleep but still this is a rather high op tempo."
"Well X said that it's good to do endurance training before needing it," Artoria said with plenty of energy. Perhaps due to her unique (Journey of the Flowers) Skill. Though it didn't change the magical energy accounting, one could certainly go further, easier, with its benefits.
"Whether you need to carry on the fight, or carry your group, that preparation will be critical," X repeated her convictions confidently.
"True though remember, Artoria, that if you use either Holy Sword too often we'll quickly run dry and then it's a fairly quick dead end," Gudako said soberly. "Especially since you're not really supposed to have Excalibur. I mean you can't get the bonus stat adjustment from being Santa in the middle of summer. Probably."
"Going beyond your limits and then dying right after the victory screen isn't nearly as heroic as people think," a nearby Chloe, watching out for any hostiles that might crop up while they took a breather, commented off-handedly. "Or you know, dying just before the final boss."
"Sometimes you just have to to actually beat the odds though." X didn't seem to think it all that unlikely or contrived. "Just remember that your enemy might do the same. And, well, Servants can 'come back' though you need people around to summon them in."
"True enough," the Archer replied. "That sort of thing gets massive bonuses - Noble Phantasms that require you to take damage or suffer some trauma etc."
"That's the world humans left us." Cat was working a pot in which she was somehow stir-frying vegetables from the area. Free Quests and even Singularities frequently had any number of mundane ingredients, something which helped a great deal in the latter which tended to be longer-running affairs.
"Chloe, I've been wondering something," Gudako commented as the Servant came to get her helping of piping hot food. Since Rayshifting moved the whole person, it was possible to stay on-site for relatively long periods provided one had all the necessary provisions and rest. After all, Singularities were essentially multi-week Rayshifts. Rather then 'go back' and go through all the cycling, they instead returned and immediately Rayshifted to the next Free Quest that was already lined up for them.
"About what?" she replied between mouthfuls.
"Rin also made a contract with Ruby, like you, so... ?"
"Uh." Chloe looked at the Master doubtfully. "Don't you have Sasaku to check the literal Servant database for you?"
Gudako shrugged. They had actually asked her and not gotten a really conclusive answer, one of the things that caused the Masters to suspect the veracity of the Ruler's Skill. "I was just thinking that you might have a clearer idea since, you know, same wand."
"Oh, I don't think they're the same. They might strictly follow a no-double rule, but that still means every World branch has a different one in it. Also, unless she did quite a lot as a magical girl, which I doubt given what she mentioned to Gudao... it's unlikely to count. Transforming once or twice won't cut it. Maybe if it involved collecting Holy Grail fragments, then you might be able to boost up..."
"All done !" Artoria and X returned with cheer and another basket of Artorium.
"Swap time !" X eyed Cat's cooking with entranced her with its distinct aura of deliciousness.
"Ok, you have a bit and watch Master. Cat, let's mix it up with the next group of mobs."
"Ingredients, Artorium, rare materials not found in the natural World, Artorium." After moving the pot to a quickly but sturdily built holder, Cat began checking her claws which served as excellent weapons. "Let's go !"
"Hmm," Gudako looked at her watch; while the item looked like one of those fitness aids that had become a bit of a fad before the Incineration, it was in fact a Mystic Code of da Vinci's design, sporting what the Rider called 'modern mystery-type visuals' which also in lieu of any obvious controls, used a magecraft-based input system. One thing that it did was perform low-power scans which, among other details, could tell the wearer their internal magical energy levels. "Still some time left. Might as well eat up, eh X ?"
"Nothing like a good hot meal after a day's work !" X accepted readily.
"It's so quiet outside," Gudako commented to Artoria while sipping some sort of herbal tea Cat had put to steep earlier. Though some of the ingredients looked like normal grass, the result was like that of a fresh green tea. The sound of X's delighted mealtime was punctuated by an explosion as Chloe took down a particularly tough armored foe, and Cat excitedly informing her comrade about a find or something else that interested her at the moment. "It's a bit disconcerting to be out for so long alone."
"It's quite a marathon, for harvesting Free Quests," the Saber agreed, understanding immediately the Master's words.
But X didn't have sufficient context to shed light on that. "I didn't think Chaldea was that noisy though?"
"It's a sort of shared... ongoing experience." Artoria ventured.
"Nothing as involved as that," Gudako clarified. "It's something like what you call 'reading the atmosphere', at least when it's idle."
"Idle?" X eyed the meat that Cat had been working on in between her vegetable dish. It seemed that the cook had elected for a doner or gyro-style, cooking the chunk in the relatively high direct heat provided by campfire flames and cutting off richly browned meat at regular intervals, turning a large hunk into a pile of fine but deeply flavored slices.
"Yes, like an idle carrier signal I think Emet would put it." Chaldea's resident Systems expert would probably have found such a characterization inaccurate, but of course she was not present to protest. "Compared to the usual background hum, sending messages is like shouting."
"I guess that means eight hundred-or-so of you can't be chatting over that," X blinked. "Even if you were speaking at the speed of thought."
"It's the equivalent of trying to communicate with loudhorns, yes."
"I guess that means you don't have any general communications system? Seems a bit odd since you have capabilities like: Rayshifting."
"There's basically a phone system, but at least for us Masters the System is useful since it's close to instant. I guess it seems odd, but we've been operating under a sort of autarky because someone would notice if a mid-sized farm was somehow using as much electricity as a small town," Gudako explained. "There's another reason to not use wireless telecommunications; far too likely to be noticed. Burning lots of magical energy is a bit less dangerous since mundane people won't notice, mundane instruments don't pick them up by definition and the Clock Tower already knows the Einzbern Estate uses a good amount of magical energy."
"There's also the Separation Order," Artoria added.
"No," the homunculus shook her head. "That's a specific subroutine of the Grand Aria System. In general the Realm has a weaker but also harder to pin down effect on things like energy signatures. The Order is so strong that you can basically fall through the world because of being disconnected from it."
"Fall through... to where?" X asked curiously.
"Void Space apparently."
"Oh. Right."
"Come to think of it, your home civilization must be quite advanced. Mundane science here is pretty sure that there's no way to access parallel dimensions, or as we call them branches, but..."
"Advanced, but using magical energy pretty much. But uh, no my ship isn't able to cross branches. Or at least that sort of thing isn't possible with anything near its load of Artorium."
"But you're here," Artoria pointed out.
"That's maybe due to my Riding Skill. I mean Sabers always have Riding after all. But you have Merlin's instructions to thank for that." X suddenly appeared stricken with a sudden revelation. "Actually now that I think of it, I don't know how to get back from here. Chaldea, that is."
"You can't just go backwards?"
"No, try 'just going backwards' in a twister."
"... well, let's start by getting the fuel you'll need and maybe our Merlin will send you the necessary information by the time we're done." Gudako tried to keep their guest instructor from panicking.
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(da Vinci's Workshop)
(Sakura)
She had suffered life somewhat, lived life moderately, loved a lot, been loved more than expected, brought forth new life and in turn ended life in a violent, bloody manner. Of course that was nowhere near enough to allow one to return after death; heroes had to go much further, push the boundaries beyond the limit of sanity and be, in so many words, purer expressions of humanity.
It was discomforting how every now and then she slipped on recognizing her own children. It was frightening to have a void of hunger that hadn't filled her belly before.
But.
She saw beyond the fabric of the World now. Unlike Shirou who had apparently come across singly due to being the 'lesser' partner in the Spirit Origin, other versions of her had consumed Servants sent by the Counter Force - innumerable across their sum total experience. Some had glutted themselves so thoroughly that they distorted their home branch until it collapsed into itself, coming off the metaphysical tree and disappearing into Void Space.
Normally, even one such experience would not be possible without being destroyed one way or another. But now...
"The main issue I'm seeing is that this reactor design is very efficient, but only runs off Artorium," Shirou shrugged. "Considering the stuff is inherently unreliable in supply, we'd find ourselves rudderless sooner or later."
"Rudders, huh?" Blackbeard had been quite excited to see not just an actual spaceship, but one from another branch. "Might you be able to sail Void Space with a ... Void Sail?"
"Possibly." Shirou turned his attention to another, arguably more pressing question. "Regardless, X's own statement is that she can make a ship incapable of warping, uh, warp. So it's also possible that this ship can warp but not cross branches, except if she's piloting it. Heh... still this sensor and navigational package is something that we can probably not only copy but improve on."
da Vinci thought this over. "Improve how? We're hardly going to just run a research project like a sci-fi serial that wraps it up within an episode, two tops."
"The simple ways; more, larger, up-powered sensors and same for the computational systems. Just adding copies of what we can see here would improve our scan resolutions and thus Rayshift range and accuracy."
"... can't we get help from other Chaldeas for navigation?" Sakura asked suddenly.
"How, we can't even pass general messages let alone swap maps?" da Vinci raised an eyebrow.
"We can ping," Shirou realized suddenly, looking back at the map projected by X's ship systems. "We can certainly message further than we can sense something with Chaldea's signature. Basically, borrow the idea of a wireless mesh network topography with a generalized distance measure..."
"Are there winds in Void Space?" Anne wondered while looking at Shirou's sketched-out diagram of Mysterious Heroine X's craft. Apparently neither being a Rider nor being a pirate allowed her to intuitively understand spaceships.
"Unfortunately, 'Void Space' sounds a lot like we know more about it, instead of being a placeholder name for something we hardly understand. Despite being surrounded in the stuff, space, whatever you want to call it. Yeah, we're really reliant on Rayshift technology which also isn't fully understood by us either," da Vinci had encountered no lack of new mysteries after being summoned into Chaldea.
"Hmm yes, without the interference of Zelretch and his gang, Chaldea would never have been able to push back against the mastermind of the Incineration, even if our Separation Order allowed us to initially survive the catastrophe." Shirou added.
"Don't worry too much about it all," Blackbeard advised the group. "We'll have plenty of chances, and meet lots of people that can push that sort of thing along. It feels like that sort of scenario, yeah?"
That it does, Sakura agreed quietly to herself. "Oh, I'm supposed to go teach Matthew now."
(Sasaku's Room)
*Swoosh*
The door opened to admit Sakura and one of Chaldea's resident mousers. At first one might have mistaken the black feline for a cat statue that was camouflaged against the similarly dark clothes of Matthew's mother, but as she in a moment's lapse let go of the animal, it immediately jumped out of her arms.
Making the landing like a skilled athlete, or perhaps a regular cat, the feline immediately made a beeline for the low table in front of it and its three seated occupants, quickly deciding to hide itself by slipping around a nearby Ruler's back.
"Ah..." Sakura sighed in annoyance at the small beast's antics. "Great... they're all super skittish now except for Fou. He just looks really concerned all the time."
"Animals have very good special intuition," Sasaku slowly extended a finger towards her companion of the moment, which rubbed its head against her thigh, apparently forgetting its alarm of seconds ago. "If you talked with Cat you can kind of get some understanding of that."
"She's unintelligible," the other Servant frowned.
One might be tempted to imagine that the cat, being a descendant of the two which had frequented the Emiya Estate perimeter during her previous Grail War, might remember their ancestors' benefactor. But of course that was nonsense, since the animals would not remember their own parents or siblings if separated for a while.
Perhaps it was because the Realm, which they associated (correctly) with safety had a similar magical energy signature to the girl, since it came from her magecraft. But no, they didn't have magical circuits generally speaking, and the cat's black coat meant it did not host one of the Crest Worms either. Unless...
"Can they sense magical energy signatures?"
"Maybe," Sasaku answered noncommittally, switching from stroking the cat's head to carefully getting a hold behind its neck. That made handing it over into Matthew's custody easy.
"Oh. Thanks." The purple-haired girl was not particularly surprised that the smaller Servant had understood what role the cat was to play in her son's training. "Since the homunculi worked it out, today we'll step up to practicing the bind-release on a cat."
"You know," Iri spoke up suddenly from her place next to Sasaku. "Why is it that though I can understand both the theory and application, I can't reproduce those effects within the general Emiya system?"
"Primarily because it's a requirement to have the use of the magic circuits of one of the Crest Worms," Sakura answered her daughter simply. "Yes, you could in principle do without it, but basically the efficiency is close to zero."
"Is that like why you can't use your normal Skills when you transform?" Matthew asked while the cat curled up in his lap.
"That's likely more related to the conceptual limitations of the transformation Skill," Sasaku commented after a moment to think about it. "Sadly, or actually probably fortunately, (Transformation) isn't some sort of standard Spell or magecraft type."
"Now that you've mentioned it, isn't it odd that everyone knows who you are even when you transform?" Iri questioned.
"Let me guess," Sakura ventured. "It's because the original Kaleidostick user, Chloe's legend is literally her transformed version, not the original person Illyasviel."
"Probably not," Sasaku shrugged, though it wasn't necessarily the worst guess. "As the thing with Skills implies, you're actually knowing me wrong because I'm not the same before versus after transforming."
"That's... oddly backwards." Matthew wasn't sure what to make of it. By this time his cat had apparently decided it was a great time to take a catnap.
"I wonder if you can use my Family's magecraft anyway?" Sakura asked the other Servant, who shook her head in response, toying with her faded light red hair. "Doru, your student, thought that might be the case but it wasn't. And in any case," she glanced in Matthew's direction, "At Servant-level, it would be very dangerous to use it on someone at just human-level."
"That's true. Oh but the difference between you and a cat isn't anywhere as great as that," the magus told her son to head off any potential second thoughts about his first live practice. "Since mastery and will equates to strength more than just raw magical energy for this, it's hard to be able to get something stuck on you without being able to also release it."
"Oh, I see "
Sakura began to warm to the topic. Really though, it had been with the help of Doru passing her some of their recorded teaching material; she herself had not taught the basics for in the years after the first couple cohorts of homunculi had mastered those enough to teach the following generations. That said, she also knew that there were ways to break accidental links externally though perhaps as Sasaku had warned, she shouldn't do so personally.
But as Doru's experiences had shown, homunculi could do so safely on humans. And Chaldea had some specialists who were very capable at 'maintenance' of links and the like.
...
Fufufu, I see that by now Grandfather's work has been totally removed from humanity, one of her sub-selves commented.
It would have been useful to know his part in helping the Grail System create Servant vessels though, she replied. The general lack of interest in developing the magecraft within the Four Houses meant that the possibility of creating new blank Servant-level, or indeed lower but still potentially immortal, vessels was left unexplored. This was at least partially because there was no obvious benefit in terms of soul-lifetime which was already the limiting factor for the homunculi who were the vast majority of the Four Houses demographically speaking.
"Ahem. So start off like you're practiced before, but instead of trying to say take hold of the cat, you're going to use something like... trying to pet it, I guess. Don't touch it near the head or heart regions either, somewhere like the upper back should be good."
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(da Vinci's Workshop)
"You know," Shirou said suddenly. "Why exactly are you a Rider?" It's a bit odd that none of the Rulers can figure out what qualifies you, since we usually see artists, inventors and so on as Casters due to the likes of Territory Creation or Item Construction."
"But I do have Item Construction."
"Yes, and there's the fact that as a Rider, your Riding Skill doesn't seem to have any rank or proper description. No, I don't believe for a moment that 'riding roller-skates' counts since they didn't exist in your time any more than sailor school uniforms."
"Muu... what are you getting at?" the Rider frowned. They had been paused at a confusing part in the analysis of X's spacecraft. "I mean, there's an older version of me who is a Caster."
"Don't you think it's interesting how as an Assassin, X has a Riding skill that lets her make non-warp capable ships, warp?"
"Ahaha, trying to warp something like size of Chaldea would be impossible... right?"
"Well it depends but we might not need to actually warp since Chaldea is already in Void Space, and unless our estimates were wrong, we can drop into it via the Separation Order. Actually trying to land it might be tricky though as it is a very non-trivial entity."
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(Notes)
Chaldea's signature is much smaller than that of a Detection Event, it might be somewhere around Free Quest level due to the Separation Order preventing it from emanating/radiating useful information to any seeker. However, Sasaku's Ruby's broadcast function is very easy to pick up on. (It's sort of like this story's version of FGO's friend list message, if you were wondering).