Disclaimer: I do not own the Fate franchise it belongs to Kinoko Nasu and Type-Moon.

This Cannot End Well

Chapter 6

"Well, it should take us about half a day to get to London." Sakura said as a stewardess took away the remains of her meal. "How do you want to pass the time?"

"Well, the kids seem to be enjoying themselves." Tom remarked, pointing to where Nagato and Little Rin were watching Transformers: Dark of the Moon.

"I think I'm just going to get some sleep." Rin said in her turn.

"You plan to sleep all twelve hours away?" Sakura asked. "You'll get fat."

Rin looked outraged at that, even more so as Tom snickered at her expense. "How about we all just get drunk?" he offered. "I mean, we spent so much on First Class, even reserving the whole section for ourselves, so why don't we just enjoy it? Five-course breakfast, lunch, and dinner, all the alcohol we can drink, and from a complete bar at that. Haven't had a job this cushy in a while, to be honest."

"…okay, I wouldn't mind doing that." Sakura admitted. "But let's not drown ourselves in alcohol when there are children with us."

Tom opened his mouth to offer a rejoinder…

…and then closed it. "Point." He admitted.

In contrast, Rin looked smug. "So…sleeping away it is, then." She said.

Sakura looked cross. "Fine then." She said, before pulling out a beam saber. "For starters, how about we share. I'm putting up my beam saber, and as…comrades-in-arms, against the evil of Shinji Matou, family even in the case of Rin here, I'm calling you both out on personal honor to reciprocate."

"Now that's just playing dirty." Tom complained before sighing. "But fine, let it not be said that a Sawyer has no honor. My plasma pistol against your beam saber…Miss Rin, what have you got?"

Rin pulled off a ring she was wearing, gold with a ruby in front, and tossed it on the table where Sakura's beam saber and Tom's plasma pistol were sitting on. "Laser ring." She said simply.

Tom's eyes bulged. "That's a laser ring?" he gaped. "How on Earth did you pull off miniaturization to that degree?"

Rin smiled and ran a hand through her hair. "Genius, that's how." She said, and Sakura rolled her eyes.

"Modest, Rin, real modest…" she said, before giving a cough. "…anyway, since I brought this idea up, I'll be the first."

Gesturing with a hand, she levitated her beam saber, and disengaging the seals disassembled it down to the internal components. Rin raised an eyebrow at the chrysoberyl revealed at the heart of the mystic code, while Tom thoughtfully stroked his chin at the now-revealed power cells.

"The external casing is made from titanium alloy," Sakura began. "Made with 90% titanium alloyed with 6% aluminum and 4% vanadium. This makes it corrosion-proof, while having endurance and durability comparable to high-carbon steel. The grip, of course, is rubberized, for improved handling."

"Is the rubber synthetic or natural?" Rin asked.

"Synthetic," Sakura replied with a shrug, ignoring Rin's mild look of disapproval. "It was easier to get, and considering a beam saber is a form of 'laser sword' common to modern fiction, it seemed to fit."

"Huh…inverted accumulation of history, or something like that." Tom remarked. "Not too sure if that actually works, but hey, it's just the grip. What about the internal systems?"

"The power source is also of modern origin." Sakura admitted. "Basically, it's a Pu-238 thermocouple…"

"Hold up!" Tom suddenly interrupted. "You telling me your beam sabers are nuclear-powered?"

"Yes."

Tom gaped. Rin gaped. Sakura looked unfazed. "It offered a steady and ample energy source with no need for refueling over extended periods of time." She said. "Pu-238 does have a half-life of 88 years, after all, and at the time of manufacture, the thermocouple would take at least thirty years before the exhaustion of the nuclear core meant there'd be any major fluctuations in the energy supply."

"…I'm guessing there's a layer of lead under that casing?" Tom ventured after a moment.

"No."

"WHAT?"

Sakura rolled her eyes. "Trust me," she said. "I have my ways of dealing with nuclear radiation."

Rin rubbed her temples. "No offense," she said. "But I get the feeling you didn't come up with the idea of using…nuclear energy, on your own."

Sakura's face fell. "No." she admitted. "It was Caules' idea actually."

"Oh."

"…Caules…isn't he the guy from that family you…um, dealt with, in the Trifas Incident?" Tom asked softly. "Your…ex, right?"

"Yeah, that's him." Sakura replied just a bit testily, before taking a deep breath. "He wasn't always an ass. Once, he was kind and caring, an intelligent young man who seemed like he'd see more than the rest of our kind usually see. And maybe he really was…it's just that he couldn't say no to his family…"

Sakura trailed off with a scoff, briefly closing her eyes while laughing bitterly. "…and who says love conquers all?" she asked with a sneer. "Love is as much a curse as it is a blessing…anyway, yes, Caules put forward the idea of using a nuclear thermocouple as an energy source. The thermocouples in my beam sabers put out – depending on when I built them, and the available thermocouples at the time – between 800 to 1000 W of power."

Tom frowned, already moving on from the previous, and unpleasant, topic, back to the matter at hand. "That shouldn't be enough to generate a plasma blade like the ones your beam sabers have." He said.

"You're right." Sakura said with a nod, before pointing at a small component. "This here is the energy converter, which takes the power from the thermocouples, and turns it into plasma. By itself, it's barely hotter than your average stove at full blast, but it's very diffuse and not very useful except at extremely short range, but that plasma is then fed into the resonance chamber…"

"…where the chrysoberyl scales it up." Rin said in awed realization. "Not just in terms of heat and concentration, but conceptual weight as well."

"Jewel Magecraft." Sakura said with a smile.

"I'm guessing these are magnetic lenses, to help focus the plasma." Tom said while pointing at a trio of rings. "I'm also seeing some kind of magical work on them, what's that?"

"You remember the radiation issue from earlier?" Sakura asked. "That's my solution. Energy is energy, no matter what form it takes. A bit of compact Formalcraft, and those magnets suck up the radiation from the Pu-238, convert it to prana, and use it to enhance their magnetic properties, while also gaining conceptual weight. Not much, but enough to work with magically-enhanced plasma."

"Huh…neat…very unorthodox, but neat…" Tom muttered.

"What's this piece do?" Rin asked, pointing at the last component, which seemed to surround the beam saber's exhaust port.

"That one's a spatial distortion field generator." Sakura said. "Not by much, to be honest, just enough to keep the plasma contained in a useful form. It breaks along the point of impact when it strikes a physical object of sufficient density, so it can be swung through air without issue. Against a person, though? The plasma will burn right through their body, and with enough heat to melt even through steel plate."

Sakura gestured again, levitating all her beam saber's components, and then putting them back together, let it fall into her hands. Then she ignited it, extending a brilliant white blade a meter long humming through the air. She just as quickly shut it off, before smiling at Tom. "Your turn." She said.

"Show-off." He muttered, before pulling out a small kit. Then he picked up the plasma pistol, and popped out a glass vial filled with some kind of clear liquid from under the barrel, where it fit snugly inside the mystic code. "My pistol takes a while to pull apart, so let's start with the fuel. That's pure, concentrated hydrogen peroxide, which is why it needs lead crystal to carry it around in. It'll eat through metal like there's no tomorrow, and don't even get me started on plastic or flesh."

"…pretty sure concentrated hydrogen peroxide works as rocket fuel." Sakura muttered.

Tom barked a laugh while unscrewing his pistol open. "It does!" he confirmed. "Which makes it very useful as raw material to make plasma with. Anyway…my pistol's made from steel alloy, technically low-carbon steel, since it only has 0.4% carbon by weight, but you could also call it stainless steel, seeing as there's also nickel and chromium, 4% and 2% each. Well…industrially, stainless steel should have at least 11% chromium, but that doesn't matter. Anyway, the metal makes the pistol durable, if rather heavy, but what's a little weight?"

"It should help when aiming." Rin observed.

"That it does." Tom said with a nod.

"How do you deal with rust?" Rin asked. "I mean, it's steel, which means it's mostly made from iron, and iron, well, rusts."

"The usual." Tom said with a shrug. "Galvanization, a thin layer of electroplated zinc on top."

"Ah, I see."

"…and…here we go." Tom said, laying out his disassembled plasma pistol on the table. "The trigger system is pretty simple, just your usual mess of levers and basic machinery to feed a jet of hydrogen peroxide into the energy condenser. You can't see it because the condenser's fused together in one piece now, but before that it was in two pieces to work on its insides. Simply put, a bit of fire and earth elemental magic to make the condenser work."

"…fire to generate plasma…and earth to contain it…" Rin muttered. "…huh…pretty simple, all things considered."

"Yeah, but even with that plasma is very hot." Tom admitted. "My grandpa's notes from before he died in Vietnam mentioned quite a few accidents when working with plasma. Part of the house back in Missouri even once burned down back in the 60s after a plasma containment breach. Killed quite a few people too…one of his notes mentioned an apprentice who literally got melted down when a plasma bottle ruptured and sent a jet of plasma at the poor bastard. Eventually, we used the same principles to generate plasma to safely collect the heat, redirecting it away from the internal mechanisms, and safely diffuse it using these vents here."

"…after experiencing the heat bloom once," Sakura remarked. "I have to say it's not a complete solution."

Tom sighed. "No, that it isn't." he admitted. "Rapid-firing this thing more than four times is practically guaranteed to be suicide. Never tried it myself, of course, but when the vents start to glow red-hot…well…best to stop firing until it cools down."

"I assume you use the same principles to keep the plasma…coherent, after it leaves the barrel instead of just…exploding?" Rin asked.

"Yup." Tom said with a nod. "It's rated for up to a distance of sixty meters, but seeing as it's a pistol, I've never really used it outside a workshop at maximum range."

"I'm guessing you have rifle and bigger variants of this mystic code." Sakura mused.

Tom smiled and winked. "Now," he said. "That would be telling."

Rin and Sakura laughed. "Fair," the former said. "One last thing, how many shots per fuel cartridge?"

Tom shrugged. "About sixteen shots," he said. "Just below your average for normal handguns, so best to make my shots count, right?"

"Considering how effective plasma can be," Sakura began. "Hard to make them not count."

"They won't if you don't aim." Tom pointed out.

"Point."

Rin nodded in understanding. "Well, if there's nothing else," she said. "I guess it's my turn."

"Looks that way." Tom agreed.

"My laser ring's much simpler compared to either of yours." Rin said more than a bit smugly. "After all, it's just an 18-karat gold ring with an enchanted ruby"

"…really?" Sakura asked, looking and sounding disappointed.

"Okay, it isn't." Rin admitted. "I tried to keep it that way, but I just couldn't focus the prana enough to generate a laser beam. So, I engraved the necessary mysteries onto the interior of the ring, and inlaid them with ether condensate to really make the mysteries sink in."

Sakura stared. Tom stared. "What?" Rin asked.

"Where on Earth did you get ether condensate?" Sakura asked.

"I stole it." Rin admitted.

"You did what?" Sakura asked.

"I stole it." Rin repeated.

Tom sighed, sitting back in his seat, one hand on his forehead. "Well," he said. "I guess this shouldn't come as a surprise, as thievery is pretty much accepted as something that just happens in our world. But, seeing as I'm an Enforcer…I'll pretend you didn't say that."

"Thanks, big guy."

"Hey, what are friends for?"

"Anyway," Rin continued with a cough. "It's basically just fire elemental magecraft refined to its logical conclusion. A beam of pure heat energy, directed at a target. Maximum range is at eight meters, past that and the beam just diffuses, enough to cause first or second-degree burns, but nothing more. And even at eight meters, while it's powerful enough to blow limbs off, well, the laser's too diffuse to cause more damage than that."

"You're blowing limbs off and you're unsatisfied?" Sakura asked in disbelief.

"Hey, at four meters or less," Rin pointed out. "The laser could blow entire bodies apart. I should know, I tested it on a reinforced goat's head, and even on a full-grown cow."

"Where did you get a goat's head?" Sakura asked incredulously.

"I stole it."

"You. Stole. A. Goat's. Head."

"Technically…"

"What?"

"Hey, the goat was dead when I got there."

"…and the cow?"

"Oh, that one I borrowed from Luvia. And yes, I paid her back for it afterward."

"Where did Luvia get a cow?"

"Oh, don't be silly Sakura. Luvia has plenty of land in Finland, including ones where they raise cows on."

"…makes sense."

Rin beamed. "So," she began. "Any questions?"

"…how fast can you shoot your laser?" Tom asked after a moment.

"Once every twenty seconds." Rin replied. "I tried it once, firing twice in about…ten seconds? It burned my finger off. Twenty seconds is the best time balancing out firing rate and cooling the ring."

"You. Burned. Your. Finger. Off." Sakura ground out.

"Hey, I grew it back." Rin protested at Sakura's tone.

"RIN!"

"Isn't that sweet?" Sakura remarked.

"Concerning, too." Rin said with a sigh, getting up from the coffee table, which was messy with half-drunk glasses, half-eaten plates of finger food, poker chips, and of course, cards. Getting a blanket from one of the chairs, she went to Nagato and Little Rin, and draped it over their sleeping forms. "While I'm glad they get along so well now, especially after their bad first meeting, they'll eventually have to get separated. I mean, it's not like Nagato can stay here."

"Why not?" Sakura said with a shrug. "His home timeline's about to get pruned. Wouldn't it be kinder to keep him here then?"

"His parents might disagree." Rin pointed out.

Sakura snorted. "If his parents think dying together with their son is preferable to giving him a chance to live in a more viable timeline," she began. "Then I've got a few things to say to them."

"Yeah, so do I." Rin conceded. "In all honesty, even from what little we've known so far, my counterpart badly reminds me of Tokiomi. No…worse…"

"Worse…?" Sakura echoed.

"Yeah…" Rin said, eyes distant and faraway, her expression bitter as she relived her past. "…she reminds me of how I used to be…"

Sakura was silent for a long moment, and then taking a deep breath, leaned over the table with a forced smile. "So…" she began. "…about the stolen ether condensate…"

"Hmm…oh, well, you see…"

Rin wrinkled her nose as she paced along the Alexandria waterfront, the stink of spoiled fish, saltwater, and garbage simply disgusting. And from the expressions of other magi present, she wasn't the only one to think so. Thankfully, they wouldn't be here long.

The smugglers who'd been caught trying to carry off the stolen materials from Atlas were already in custody, with agents from the College of Law already collecting statements and gathering evidence and whatnot. Atlas personnel were recovering the stolen materials, while other magi were simply keeping busy.

As in keeping busy by presenting a token presence for their families, cliques, factions, and whatever else you might call it.

"Well," Rin thought. "It's not like I can be too disparaging. I'm here doing just that for Lord Zelretch."

Then she blinked, as she noticed one of the Atlas containers had been damaged in the fighting earlier. Not much, but enough to expose the glass-encased rods of ether condensate.

Normally, Rin wouldn't even consider doing this…

…but she was tired, irate, and very bored from having to stand around in a stinky and dirty place such as this, when she could be doing her research. Wandering over with cautious glances to see if anyone was looking, she quickly snatched a rod, and hid it away in a coat pocket before walking off while whistling to herself.

Sakura fell back into her seat, laughing away at Rin's description of how she stole the ether condensate. "And they never noticed?" she asked.

"Would they really strip-search an apprentice of the Wizard Marshal?" Rin asked back. "I mean, they noticed some of the ether condensate was missing, but chalked it up to the battle damage that opened the container in the first place."

"I'm sure that ring used only a small amount of condensate." Sakura mused. "I'm guessing you still have the rest in stock."

"Could be useful someday, you never know." Rin said with a shrug.

"And the goat's head?" Sakura asked.

Rin sighed. "Like I said, the goat was already dead when I got there." She said. "I doubt the farmer would have cared if the carcass was missing its head."

"How did it die, anyway?" Sakura asked curiously.

"I…honestly don't know." Rin admitted. "I was headed for a butcher to buy a goat's head, but on the way, I saw this goat lying freshly dead by the side of the road. It didn't look like roadkill, so…maybe it was just old? Anyway, it wasn't on private property, and it was already dead, so…"

Rin trailed off with a shrug. Sakura looked a bit skeptical, but decided not to press. "And the cow?" she asked instead.

"Well…" she began, looking and sounding guilty. "…promise you won't judge?"

"Huh?"

"You see…"

Rin raised her fist, the ring pointed at the cow standing innocently a couple of meters away. There was a flash of red light, and before the cow could even make a noise, it simply flew apart in an explosion of torn meat, broken bone, boiled blood, and hot steam.

Rin and Luvia stared, aghast at the devastation the former's new mystic code could cause. Then the latter blinked, her expression thoughtful and calculating. "How much for the new mystic code?" she asked.

"…is writing off the cow enough?" Rin asked after a moment.

"More than enough," Luvia admitted. "Anything else you'd like in exchange for your research notes?"

"What are you offering?"

"Well, what do you want?"

Rin thought it over for a few moments, and then she noticed Luvia. Luvia, who was wearing only a sleeveless, somewhat low-cut country dress here and now, showing off quite a bit of her cleavage along with those lithe arms with her porcelain-like skin…

…Rin licked her lips.

"Well…"

"Did you seriously proposition your timeline's version of Luvia?" Sakura asked incredulously.

"What?" Rin protested. "She's very pretty! She smells nice too. And I could spend a whole day just snuggled up against those pillowy breasts of hers."

"Well…if you put it that way…" Sakura admitted, looking away with a faint blush. She too had noticed that Luvia – well, Lord Edelfelt now – was attractive even to her. A shame about her attitude in the past, in hindsight at least.

"…bisexual…?" Rin asked in a small voice.

"Eh…I just find both men and women attractive…but you know Luvia's our cousin, right?" Sakura fumbled.

"Yeah, so what?" Rin said with a shrug. "Besides, we're both women, so it wasn't like anything was going to become of it."

Sakura looked at Rin flatly at that. Rin met her gaze evenly, and after a few moments, Sakura smiled teasingly. And before Rin knew it, she was pressing herself back against her seat, as Sakura came over, and leaning in just a few inches before her, took her gently by the chin.

"You're quite pretty yourself, Rin." She said softly.

"R-r-really?" Rin asked, sounding and feeling very breathless. She knew they shouldn't be doing this, or thinking or even feeling like this, this was her sister after all, but even so.

"Yes, you are." Sakura asked, still smiling as her eyes fell to half-mast, Rin's eyes following suit.

"Oh…um…thank you…" Rin began with a blush, suddenly feeling very hot. Not knowing what was coming over, before she knew it (again), her hand was going up, rubbing against the side of her sister's face, the other woman leaning into her touch. "…you're very pretty too, you know."

Sakura smiled wider, leaning in as Rin leaned forward…

…only for Tom to return from the men's room, and stare in shock at the sisters about to start making out.

"Okay, what'd I miss?"

A/N

Following after the example of the previous fic's science fair…er, I mean, magecraft exhibition at General Fundamentals, our heroes compare mystic codes to pass the time (at least at first).

Then we have a heart-to-heart between sisters, with Rin admitting she's bisexual (which she actually is) and Sakura also – somewhat – admitting likewise (and which she also canonically is). Followed by (almost) surprise incest, LMAO. Hey, it was just (almost) a kiss.