Disclaimer: I don't own Fate/Stay Night.

A Reversal of Fortunes

Prologue

"I'll admit that I was unfair and perhaps even cruel to your sister." The goateed man in red told the little girl in red and black. "Ever since she was old enough to understand the world around her, she was raised with the knowledge that one day she would succeed me, inheriting the power, knowledge, and wisdom of our family, and with it the mysteries and miracles we are capable of bringing into reality."

The little girl was silent, attentively listening to her father. "I will be honest with you Sakura." The man continued. "By all rights she should be the heir. She possesses a flair for the Art you lack, despite the undoubtable effort you've poured into fulfilling your responsibilities ever since I made my decision. Her Five Elements would have been a natural fit with the Jewel Magecraft of our family, even without taking into account the unparalleled versatility of such a gift. In contrast you will struggle to apply your gift to our family's Art, perhaps even necessitating a partial reconstruction in and over time. And yet I chose you to carry on our legacy. Do you understand why?"

"No." the girl speaks, her voice soft.

"It's because the ultimate goal of the magi is to reach the Root." The man says to his daughter. "Compared to attaining that goal everything else is secondary, and no sacrifice is too great."

"Father…"

"I have sacrificed my responsibilities as your father, and as your mother's husband." he continues. "I have sacrificed our family, our happiness, your sister, and even your smile."

A hand reaches out, caressing the girl's face and sliding down to cup her chin. The man smiles. "You have never smiled at me like you used to, ever since that day so many months ago." He said sadly. "And even your beautiful eyes, are shadowed now. It is painful to see, but I do not regret it."

"Father…"

"I have placed a terrible burden on you, Sakura." The man said with a sigh. "After all, to carry on our legacy, you must achieve a miracle that surpasses your sister's natural genius. But I do not regret it, because despite the risk born of your unequal individual talents, the legacy you could leave behind is greater. Rin's Five Elements compose the World, but your Imaginary Numbers govern the immaterial. And the Root does not exist on the material plane."

The girl lowers her face, and after a moment her father kneels down to her level. Taking her hands, he places a book in them, followed by a ruby medallion on a silver chain that glowed from within. He smiled sadly at her.

"I will not ask for your forgiveness," he said. "Instead, as a magus I will ask that you give meaning to all those sacrifices. Do not fail. Carry on our legacy. Be all and the best you can be, Sakura."

"I will, father." The girl whispers, and with a short and sad laugh the man leans forward, gently bumping his head against hers. Pulling back, he kisses her on the forehead and hugs her tightly before letting go and getting to his feet.

"Goodbye Sakura." The man said. "Take care of yourself, and your mother."

With a last wave the man turns and leaves, leaving his daughter to look after him down the road in the afternoon light. And then, her face twisting unhappily, she shouts after him. "Father!" she shouts, causing him to stop and look back at her. "Please, come back. Come back to us, to mother and me. Please, come back."

For a long moment father and child looked at each other in silence, and then the man smiles and nods. "I will." He said. "I will return to your mother and you."

And for the last time in his life, the man beholds his daughter's smile, and blinking away his tears turns away to leave.

"Liar…you're a liar…you never came back…you left us behind…you left mother and me…father…"

"Sakura…Sakura…Sakura…"

The bookish teenager blinked away at the insistent voice and gentle pushing of her shoulder, and she pushed herself off her desk. "W-w-w-what?" she mumbled, rubbing at an eye before picking up her glasses and putting them back on.

"Sleeping at your desk again?" Luviagelita Edelfelt said with a sigh. "That's so unprofessional."

"It's only unprofessional if someone catches you in the act." Sakura Tohsaka said with a yawn. "And technically this is my private research space, isn't it?"

"Oh but I did catch you didn't I?" Luvia asked with a laugh.

"I wonder why it's even called private then." Sakura said, folding her arms on her desk and setting her head back down.

"Hey, don't go to sleep on me again!" Luvia said, tugging at a surprised Sakura who yelped as she was pulled out of her chair. "Come on, I've got something to tell you."

"Hey I'm not finished here!" the younger girl protested, clinging to her desk.

"Sure you were, otherwise you wouldn't be sleeping at your desk."

"Fine, fine, just let me finish backing up my data!"

Tugging her arm free and muttering to herself, Sakura turned back to her desk and pressed a button on a metal panel set into the wood. A wafer-thin screen of polished quartz flashed to life, rapidly scrolling with numbers. "This might take a while can you wait?" Sakura asked.

"I'm in no hurry."

Sakura nodded, leaning forward with her hands on her desk, her eyes following the data as it scrolled down the screen. As she waited for her data to finish backing up, her thoughts strayed back to the dream, and she sighed.

"In light of what's coming it's no surprise I'm dreaming of back then I guess." She sadly thought to herself. "It doesn't make things any less distracting or depressing though."

Sakura pressed her left hand against her right arm, but didn't say anything. Neither did Luvia, who was standing behind her and saw the action. Sakura didn't remove the hand though, and continued watching as she was.

Minutes later and the screen flashed a message. Sakura dismissed it, and entered a command. The screen flashed again, and then a metal panel opened, ejecting a cylinder of polished crystal. Sakura took the crystal and closing the panel switched her logic engine off.

"So," she began as she put the cylinder away along with others like it. "What's happened? You aren't usually this excited, or at least don't let it show this much."

"I'll tell you the details over tea." Luvia said with a grin. "But I'll say this much: I've got a contract from a major family – the El-Melloi."

"Seriously?" Sakura asked in surprise, looking over her shoulder.

"Yes!" Luvia said happily. "I'm sure there's a lot of politics behind it, but even then they wouldn't gamble on someone whose skills they can't count on. That family hasn't exactly been doing the best over the past ten years no?"

"I guess not." Sakura agreed, walking across the lab where she opened a safe and placed her memory crystal box inside. "Congratulations."

"Come on," Luvia said surprisingly petulantly. "Is that really all you're going to say? You sound so overjoyed too."

Sakura laughed good-naturedly. "Luvia you're basically bragging about yourself." She pointed. "Until I get the details it's not really something I should be praising you on, seeing as it'll just feed your ego."

"And you're not egoistic yourself?"

"Do I look it?"

"Hmm," Luvia hummed, giving her cousin a once-over. "Point, you look like a librarian, as usual."

"That's entirely my choice and you know it." Sakura said, surprisingly offended. "The look works for me, and it keeps annoying attentions away."

"You don't have to look plain to do that you know." Luvia said theatrically and with matching motions. "Yours truly is an example in that regard."

"And how many prospective suitors do you have to entertain every month?" Sakura asked while putting her research materials in order.

"Ah, you play dirty, bringing something like that up!" Luvia snapped. "Still, that's a good point I guess. Though it's unavoidable in any case. We're both heiresses, but compared to you my name and rank bring greater obligations."

"You're probably right." Sakura said with a sigh. "And I'm probably just putting off the inevitable just like you are."

Sakura sighed again, and closed her desk drawers. "Anyway enough about this depressing topic." She said, taking off her white coat. Walking over to a coat hanger she hung it before turning back to Luvia. "I'm guessing there's more?"

Luvia grinned and walked closer. "You're going back to Japan in a while right?" she asked.

"In a few months, yes why?" Sakura asked before the coin dropped. "Are you telling me your contract is in Japan?"

"Not just in Japan, but in the same city as you: Fuyuki." Luvia said cheerfully. "And not only that, look!"

The blonde girl unbuttoned and then pulled back a sleeve, exposing something that made Sakura's eyes go wide. "So," Luvia said with a business-like smile and tone. "Shall we discuss a possible alliance in light of our shared interests in the coming war, cousin?"

A/N

I've read a couple of works here and on Beast's Lair about the siblings being switched in their roles, so I decided to give it a go. It's certainly an interesting POD, and one rarely explored. It'll be rather challenging too, seeing as Sakura's lack of any 'normal' elemental affinity makes Jewel Magecraft awkward and cumbersome for her to use, as well as what the Matou magecraft could pull with all Five Elements. And in the latter case, it's natural: Sakura in canon had to be given an affinity for water through her 'training', but even then her magecraft was pathetic without backup from Angra Mainyu. Here though that won't be the case, for either sister, for reasons that will eventually be seen.

I also wish to explore the Tohsaka-Edelfelt connection, which has been confirmed in Fate/Apocrypha. Sakura there is mentioned in passing as having been adopted by their relatives in the Edelfelt Clan (the Matou having rotted away and forgotten entirely in that timeline) and is actually Luvia's partner. Hopefully if they give her an appearance there the artists will remember that she shouldn't have purple hair and eyes, which were given to her by the Matou, and aren't her natural colors.

Well, let's not put overextend this A/N, so I'll finish by giving you three guesses what Luvia's contract involves, though you're only going to need one.