Disclaimer: I don't own anything that would count as fandoms here. Therefore, to all the IP holders out there, please don't sue me over this.

Xamusel: I got this idea a while ago, back when sakurademonalchemist first uploaded her drabble for Cascade Effect. Naturally, I wanted to try my hand at it, but that didn't mean that I was going to do so without permission from the original author, anyway. Well, this is the case where I begin writing it… so now, let the story begin.

Fate/Zero Cascade
by Xamusel

Chapter 1

It was a relatively normal day in the life of Tohsaka Aoi, mother of very recently born Tohsaka Rin, when her life shattered like a glass window against a rock.

Aoi was at the park with her firstborn daughter, having only the week before gotten pregnant for the second time, rocking her eldest in the portable cradle she was in. I wonder if she'll take on any traits from either myself or Tokiomi, she thought. Either way, I know she'll be a good Magus, though I do hope she'll be a better person, much like Kariya-kun. She shook her head wistfully. Although I still call him as such, I can't call him by name alone, due to cultural rules that I need to abide by.

Still, she noticed something out of the corner of her right eye, causing her to turn away and see what it was… Is that a phoenix? She certainly never expected one to appear outside of the enclaves of Wizardry and Witchcraft. I know it's not a familiar, but what's one doing here of all places?

A cracking noise from where Rin was being rocked interrupted her thought process, causing her to jolt her head back to facing where her daughter was supposed to be… she was gone from her portable cradle. "Rin?" she asked, not believing that it happened. A couple seconds later, she raised her voice to ask, "Rin?!" Finally, an additional few seconds later, she cried out, "RIN?!"

The police took a few more minutes to arrive, with enough time for Aoi to frantically search all over the place for her daughter.

Tohsaka Tokiomi was mad… no, that was too soft a word for this occasion. He was absolutely livid that something happened to his wife without any way to prevent it. Whoever did this is going to get a Fire Element spell to the face, he thought, secrecy rules be damned! I want answers! Who did this?! Why did they do it?!

Still, he marched on over to the police station, where he was told his wife would be at. He didn't know what was going on, but he was determined to find out, regardless of the circumstances.

Upon reaching the police station, he opened the door and headed on inside, but calmed himself slightly so that he could go see his wife and the police in charge of consoling her. "Tohsaka Tokiomi here," he said to the receptionist. "My wife is supposed to be here, after our daughter was abducted from her cradle in the park."

The receptionist nodded, before she said, "Room 1-D, Tohsaka-san. Take the left corridor, and it's the second door on the right."

Tokiomi nodded and muttered a quick thanks. He walked briskly to where his wife was, where a rookie police officer was standing guard. "Excuse me," he said to the rookie. "My wife, Tohsaka Aoi, is inside this room. May I enter?"

To the rookie's credit, he said, "I need to run this by the chief, sir, but I believe so." He then took out his radio and radioed the chief. "Chief Hasegawa, Tohsaka-san's husband is right outside the room. Should I let him in?"

There wasn't a reply right off the bat, but the door opened a few seconds later. "Ah, you must be Tohsaka Tokiomi-san," Chief Hasegawa said. "Please, come in and help us figure out what's going on."

Tokiomi nodded, before he entered the room, the door closing behind him. "Now," he said, "I know my daughter was kidnapped. However, I don't know what happened to cause it."

Chief Hasegawa nodded, before he picked up a video cassette. "Your wife was telling us she saw something out of the corner of her right eye, turned to look at it, and then heard a cracking noise a short bit after that. She specifically said she didn't see the kidnapper, but thought the sight that caused her to look away was like a bird made out of fire, or so she said," he answered. He then put the cassette into the VCR, letting it play out. "I tracked down her location in the park at the time via the CCTVs that were in the park, so we'll be able to get a clearer understanding of what happened."

At first, the footage was going on as normal, even if the camera recorded from Aoi's left going to her right. A few minutes into the video, however, Tokiomi saw the bird in question, prompting him to exclaim, "Pause the footage!" After the footage was paused, which took a couple seconds to do, he saw something strange in the filmed event. "Is it just me, or is that man's head appearing without the rest of his body?"

Chief Hasegawa looked incredulous at the footage. "I did not know that was even possible..." he admitted. "I guess this means the culprit is a magic user of some sort?"

Tokiomi and Aoi shared a look of consternation.

Around nine months later, Tokiomi and Aoi were welcoming into the world their second child, a daughter they named Sakura. Officially, the case was cold on finding Rin, but Tokiomi never gave up on finding her. It was a rough time, especially when the Japanese Ministry of Magic came knocking on their door and had to be told why they were supposed to know what happened to their firstborn. Boy, that experience wasn't pleasant, not in the least. Tokiomi had to restrain himself from throttling the Wizards and Witches in question.

Still, they had gotten some answers from the Ministry. Apparently, a Western Wizard thought it was a good idea to enter the country and abduct the child in question. Who this Wizard was, they didn't really know, but it was someone high up in the ICW. That was all they knew about the situation.

Either way, Tokiomi was going to convince Aoi to try for a third child, but she adamantly refused. Her mind and her heart seemed to be in agreement, considering Rin was abducted shortly after they tried for Sakura, which meant there was no chance of that happening. She didn't care if her thoughts were illogical, she didn't want to risk it at all.

Tokiomi wouldn't admit it, but he had no other choice in the matter. He needed to make Sakura his heir, especially in the case where Rin remained missing. He still would look for her, but he needed to know where she was at, and that wasn't looking to be a pleasant experience.

Still, he was preparing for the time when the Grail granted him his Command Spells, so that he could get his truest wish from the wish-granting device. Of course, originally, he would have done his best to get access to the Root of All Things. However, with Rin no longer there, he wished for one thing only. He wished to be there and prevent Rin from being kidnapped in the first place.

Hyacinth Potter loathed her life to that point. She had many reasons for that, but the majority of those reasons had to do with her 'family'.

No, she didn't care what the people around her said, she refused to believe or acknowledge that she was related to them whatsoever. Not to Vernon, not to Petunia, and especially not to Dudley.

It was the day she was supposed to turn seven, and nobody dared to wish her a happy birthday, not after the one time back before she first started primary school. Apparently, Petunia and Vernon tried to make her life even worse by refusing to acknowledge her birthday, and even threatened everyone into following suit. There was someone who wished her a happy birthday, but it seemed like that person vanished without a trace. Oddly enough, she heard digging in the middle of the night after the fact… not that she was allowed to look into what the digging was for, but she could tell it was in the back yard.

Anyway, she was out of the house for the majority of the day, since she did not want to be stuck with the chores again… it was after lunch that she left, and she refused to return to the house until the next day. She really didn't want to deal with the crap her so-called family was going to give her, even if Dudley was giving her less of it than usual. She didn't know why, either.

It was almost time for the Dursleys to return home, and she was hoping they wouldn't care enough to go looking for her. Her life was already terrible to begin with, no need to let them make it any worse.

Fortunately for her, she knew how to camp out in the woods without much in the way of preparations. It was just going to be a right pain to do it in such a way that the well-meaning adults would be disinclined to send her to her supposed residence, even if she'd done it before… once… and with extenuating circumstances helping her.

Still, she didn't pay attention to her path headed to the woods, because she tripped on a rock that was jutting out of the ground. As she fell to the ground, she controlled herself well enough to keep the outcry down to a gasp. She didn't want to be caught by whoever was supposed to be monitoring the surrounding area for children running away. Even still, she scraped her right hand on the ground and barely gave a wince from that.

It wasn't the first time she got hurt like that. The first time was when she fell from a tree after Ripper, the pet dog of Vernon's older sister Marge, was caught trying to bite her and had chased her up a tree. She broke her arm from the fall, which would've been hard to cover up in time for school, since it was the Sunday after the start of the new term two years prior. Therefore, Petunia had to drive her to the hospital and get her checked over by a doctor, which… okay, that was undoubtedly the nicest thing she'd ever done for her, because she'd been missing a lot of immunizations by that point. Who knew?

Without much in the way of keeping healthy, she simply found a small creek and washed the blood off of her hand, making sure to staunch the bleeding after the fact. After having sufficiently done so, she washed the blood off of her other hand, never noticing the strange pattern that appeared on her right hand.

A few minutes later, she found herself in front of her favorite tree, which was still young enough to grow into a bigger tree. She began climbing the tree, feeling more than a little safe from what was going on in the neighborhood she left, especially the Dursleys. Soon enough, she found herself at the point where she could see the stars, which was near the top of the tree.

After a few seconds, she saw the first star of the night, which prompted her to think of a wish. She knew logically that wishes were impossible to grant, but the sense of mystery was enough to make her want to get a wish granted by the stars.

"Star light, star bright, the first star I see tonight," Hyacinth began her chant. "I wish I may, I wish I might, have the wish I wish tonight… I wish I had a friend or someone who cared enough to stick around, one who wouldn't be chased off so easily by those people… and…" she paused slightly. "I wish that we could learn of whatever life is outside of our solar system, or even outside of Earth itself, too."

The strange pattern on her right hand seemed to flare up with an unknown heat. As the heat flared up further, she could feel a sense of power from it, even as the pattern glowed a bloody red.

On the ground near her, she saw a strange circle form with all sorts of odd symbols.

She could feel power coming from the circle, as a man appeared.

His hair was spiked and was pure white. His skin was a tan that could only come from long hours in the sun. His clothing was so obviously foreign that he would stand out in the drab neighborhood of Surrey within seconds of being there. He was also tall...much taller than her gym teacher who was the tallest man in the area. He wore boots that were obviously meant for hard combat, and the sort of easy confidence you'd expect from someone who had been in a lot of hard fights and knew how to handle any sort of combat situation.

In short he was the most interesting thing to show up in Little Whinging, and it really made her wonder what the heck was going on.

The man had the most beautiful amber colored eyes she had ever seen… it was almost like looking into the sunset.

"I ask of you... are you my Master?"

She blinked.

"What?" she said baffled, staring at him.

That seemed to throw him off, as he looked up and spotted her. A strange sort of recognition flickered through his eyes.

"Why are you in a tree?" he asked.

"Because I don't want the adults to see me. They'll make me go back, and I would rather sleep outside," she replied honestly.

Something in her gut said to trust him completely, and since her instincts had never steered her wrong before she decided to go with it. Besides, the man was rather fascinating.

"Aren't you a little young to be camping alone?" he asked.

Ugh… I thought he wasn't like the rest… she thought. Then again… it's possible he can tell better than to force me back to that place, right?

"I'm not that young! I just turned seven!" she frowned at him.

A light dusting of humor crossed his face.

"What's your name?"

"Hyacinth. Hyacinth Potter. What's your name Mister?"

"I don't remember."

Hyacinth looked at him sharply.

"If you don't want to say what it is, then at least have the decency not to lie to me," she pouted. "I hate liars."

The man gave her a measuring gaze.

"Fair enough. You may call me Archer," he said after a moment. "Miss Hyacinth, do you mind answering my question from earlier?"

She looked at him in slight confusion, before she realized what he meant. "Well, I'm old enough to know that the residence I stayed at is so terrible, and yet everyone seems intent on keeping me there… I don't even know why, mister Archer," she answered, barely holding back her tears.

He quickly and carefully climbed up the tree, reaching her within the minute, before he allowed her to cry into his chest. That simple act would be enough to let out all the stress related to the abuse she went through. Soon enough, she was sleeping, content for the first time in her life.

Well, this is a shitty life, Archer thought as he sat in the tree, little Hyacinth asleep in his lap and arms. I have to wonder, is this because of the Counter Force requiring my attention? Am I required to kill people to preserve the safety of the world? A strange mental ping occurred in his head, as if telling him something rather important. Ugh… very funny, Alaya. As if the Macross will show up in the next calendar year…

Archer, otherwise known as Counter Guardian EMIYA, was confused in the role he had to play for this summons. Then again, he knew that he couldn't exactly say no to Saving someone, especially if they looked an awful lot like a younger Tohsaka Rin. Although… was his boss outside of the Grail Wars trying to tell him something outlandish?

Oh, wait, it's the Grail itself telling me stuff… he thought. Now… what point in the timeline am I in right now? Last I checked, the surroundings do not match the early to mid 1990s, and it's in the UK to boot… good grief.

Before he could get any further information from the Grail, however, he felt magical energy akin to a Wizard's sensory spell flow into the area from outside the forest. What's a Wizard doing in this reality? He thought in confusion. I thought this was a realm free from the Ministry of… Magic… oh, wait, my mistake. Hyacinth is supposed to be a female Harry Potter, isn't she?

Still, with some quick thinking, he prepared a defense against being detected by this spell for himself and his Master, in case this was a case of a Death Eater trying to find Hyacinth. He Projected a copy of the Invisibility Cloak Deathly Hallow, allowing the two of them to be hidden with some success, even if he didn't know what the degree of success was at the time. He knew it would only be a matter of time, but he also knew that the spell needed to pass them by, which was why he needed to use Death's Cloak.

If only he knew what the end result would be from his actions in protecting Hyacinth…

Within the deep void of space…

"Commander! Are you alright?"

"I'm fine, Crewman. I must've bumped something by accident."

"What did you bump that caused you to bleed?"

"I'm bleeding? What are you… oh. I see now."

"Commander, this is serious! You need to see a doctor immediately!"

"Very well, I'll go see a doctor about this spot of bleeding. Now, set the Fold Coordinates to T-00000."

"Sir, what's at T-00000?"

"I have a feeling we'll be uplifting a new species."

"A new species? Do you mean it, sir?"

"I'm positive. Even if they're Micronians, they need to be uplifted properly."

"I hope you're right…"

Near the center of the galaxy…

"Fellow Councilors, I have received word that one of the Specters is requesting permission to chase after a criminal."

"Why do they need permission, Councilor Vader? It's not like this criminal they're chasing is going past the allowed space, are they?"

"Actually, the criminal violated a major decree, and opened a Relay leading outside of the Terminus Sector."

"Exactly. Thank you, Councilor Squid… why did you choose that name, again?"

"Because it was easier for everyone else to remember that instead of my actual name."

"If I may get the meeting back on track…?"

"Sorry, Councilor Tevos. The criminal had vacated allowed space by leaving through the until now unopened Relay 314, which is why the Specter requested permission to go after this one… a certain Sidious Arterius."

"Who is the Specter pursuing?"

"Oddly enough? They never said their actual name. They called themselves Agent Alpha."

"Ah, it's Agent Alpha. Tell them 'permission granted' and let them carry on."

"Are you sure, Councilor Tevos?"

"I'm more than sure about this, Councilor Electrum. Now, please have everyone call you by your actual name from now on."

"You're the only one who can be bothered to remember it, though, Councilor Tevos. Nobody else can."

"Have you tried getting people to say it right?"

"Yes."

"…"

"…"

"See what I mean?"

Over in Fuyuki City…

"Tokiomi-kun, why aren't your Command Spells visible any longer?"

"That's what I'm trying to figure out, Father Risei. It's like another member of the Tohsaka clan summoned a Servant before I could do it… wait, could it be Rin who summoned one?"

"I'm not entirely sure, but it could be, Tokiomi-kun. I'll have one of my contacts look into this."

"Which contact are you thinking of?"

"Someone who works within the Executors… codename: Bow."

"Do you have a name for this Executor?"

"I do, yes. Her name is Elesia Delacour, but she goes by the name Ciel these days."

"Alright… hopefully Ciel-san can help find Rin and bring her home."

"With her Servant, maybe?"

"Of course, Father Risei, that went without saying."

A/N: Okay… this took me way too long to actually write down. I apologize for this delay. I think this whole project started about a year ago… don't quote me there.

Anyway, as for the nature of this story, I'm sure you can figure something out about the crossovers. Not gonna lie, this story is one of the cases where it's better to have some form of plan in mind for where to take it, but I didn't think to write down the plan in advance. However, I do have an idea as to what will happen to the Dursley family, and it will involve what I mentioned earlier in the chapter.

I'll leave it at this for now, people, but please keep in mind that I'm going to cover the Fourth Holy Grail War in its entirety here.

Until next time, guys. ~Xamusel