Theory and Relevant Decisions in Siberia
by Starhawk

He should have known it would happen in Siberia. He'd gone there once, after the Time War, expecting trouble. He hadn't found it. All he'd found was exactly what had been there before, minus his own people, and in a numb sort of way he had been strangely reassured. Some things went on no matter how the universe rewrote itself. The constancy of it all would have tipped him off, once upon a time.

It all started the day he asked Rose what she was thinking about. Well, actually, he asked her what she was doing lazing about in the kitchen when she'd clearly finished eating and there were uncountable things just waiting to be seen. But he meant what was she thinking about, because she was staring at her coffee cup like it might start speaking to her at any moment.

She lifted her head, looked him right in the eye, and said three words he'd always secretly hoped to hear. Words that would prove beyond any doubt that he had been right to ask her twice. Words that hadn't come right away but now seemed to represent something of a revelation to her.

"I like aliens," she declared.

He beamed at her from his place in the doorway. "So do I! It works out, doesn't it, since we're both traveling with one."

"Let's go and see some," she insisted. She paid no attention to the reminder. "It's been so long since we've seen actual aliens. Well, aliens that aren't trying to kill us, anyway."

Since aliens that were trying to kill them did comprise a large percentage of the people they'd met recently, he supposed he should count himself lucky she wasn't turned off the lot of 'em. The fact that she wanted to actively seek them out was delightful news. Especially since he liked humans, he really did, but he was getting a bit tired of Earth and he wouldn't mind stretching his legs a bit, so to speak.

"Off we go then," he said cheerfully. "I know just the place."

Her smile echoed his, and she'd never needed more convincing than that. "Now you're talking!" She bounced up out of her chair without another glance at her coffee cup.

The constancy of it all would have tipped him off, once upon a time. Some things went on no matter how the universe rewrote itself. All he did was exactly what he'd done before, minus his own people, and in a distant sort of way he was aware of that. But now he had Rose, she had an insatiably curious nature, and he had a history.

He should have known it would happen in Siberia.

The strangest thing about it was that it looked so normal. That was her first impression on stepping out of the TARDIS, and then she decided that she'd been traveling with the doctor too long if this lot could look normal to her. There were aliens--people, she reminded herself--of all shapes and sizes, see-through and stone-like and lit up like Christmas trees.

It wasn't what they looked like that she noticed first, though. It was the way they were acting: like people, like the aliens on Platform One, like it was the end of the day and they were just on their way to the pub for a drink. No one on the street was shooting or stealing anyone else's skin or trying to take over the world... although knowing the doctor, that would come later.

"Time travelers," she said, looking back at him for confirmation. "Everyone here? Really?"

"Yup." He seemed immensely pleased with himself. "No one gets into Siberia without wandering, at least a bit. Doesn't recognize biomass that only moves linearly. It's invisible. Just walks right through, doesn't see a thing."

She was tempted to decide the answer to her question was yes and just forget the rest of it, but it was one of those things he said that she thought ought to make sense, only it didn't. "So, what you're saying is, there could be people who aren't time travelers here right now, and they wouldn't see any of this?"

He shrugged. "Could be. Why d'you come if not for Siberia, though? Pretty boring place otherwise, just a chunk of rock. Not a lot of visitors."

"Yeah, and that's another thing." She was staring around, trying to see the busy square without the people and the lights and the colors. She couldn't do it, so she turned back to frown at him. "Why d'you call it Siberia? That can't be its real name."

"And why not?" He pretended to take offense. At least, she was pretty sure he was pretending. "You think you were the first ones to come up with that name? Maybe you stole it from us! Siberia, indeed. More like Copycat Planet."

She grinned at him. Definitely pretending. "We didn't steal it, though. 'Cause if we had you wouldn't have said 'maybe.' So why d'you keep calling it that?"

"That's what it sounds like," he said, like he hadn't even protested. "In my language, anyway, but a lot longer. Siberia's quicker to say."

"What's your language like, then?" She was intrigued by the mention of anything to do with his planet, since he was usually so close-mouthed on the subject. "Did your people come here a lot?"

"Sometimes," he said curtly. "Here, come have a look at this."

She rolled her eyes, but only after he'd turned away and she was hurrying to catch up, because she didn't really want him to see her do it. He didn't have to tell her anything about his people. She wanted him to, though, and if he was going to drop hints like that then she wasn't going to just ignore them.

"Crystal ball," he was saying, standing outside a big round glass thing. "Step inside."

Someone almost barreled into her and she jumped out of the way. She was about to make a snarky comment when she heard the word "Sorry!" drift back to her. Okay, so she wasn't invisible, then. Good.

"What is it?" she wanted to know, eyeing the glass thing.

"Just a toy," he assured her. "In you go!"

She put both hands out to steady herself against the glass doorway, looking around curiously as she stepped into the spherical thing. It had been transparent on the outside, but it was silver inside and she could see her reflection plain as day on the curved wall in front of her. She glanced over her shoulder, half-expecting the opening she'd come through to have closed behind her, but no--there was the doctor, leaning against the "doorway" and smirking at her.

"What's it do?" she asked, reaching out to touch the silver lining.

He just nodded over her shoulder, and she looked back at her reflection in time to see it turn away. She frowned, trying to figure out what angle it was reflecting her at. The whole inside of the thing was shiny, shouldn't she be able to see herself all around?

Then she heard her own voice say, "But that doesn't make any sense!" Her reflection turned back to study her again, once more doing what she was doing. Except her reflection looked more surprised than puzzled.

"What--" She stared at herself. "I didn't say that!"

"So if I know the future," her reflection said slowly. The rest of the sentence was drowned out by the doctor's words.

"Not yet," he agreed from behind her. "But you will. It just projects you ahead a bit, reflects what you will do instead of what you are doing. Perfect crystal ball."

"That's impossible," she protested, still watching herself in the silver wall. Like a backwards mirror, she realized suddenly. With the silver on the near side and the glass on the far side. "How does it know what I'm going to say?"

Her reflection had started talking while she was, and all she heard was, "All I've got to do is not say it, right?"

"It doesn't 'know' anything," the doctor's voice told her. "It's not alive. It's just a little bitty temporal distortion." She turned to stare at him, and he added, "The back wall there's reflecting a slightly different time than the one you're in. A future time."

"But that doesn't make any sense!" she exclaimed. When she realized what she'd said, her eyes widened and she looked at her "reflection" in surprise.

"That's right," it was saying. She thought it sounded a bit cheeky. "D'you hear that?"

"It's not off by much," the doctor said cheerfully. "Just a few seconds."

"Oh, that's not fair," her reflection complained. It sounded a bit petulant, to her, and she wasn't sure she liked it.

"So if I know the future," she said, giving the wall a speculative look, "I should be able to change it, yeah?"

She could hear the grin in his voice as he said, "You won't be the first person to try."

"Come on," she insisted, talking over her reflection. "I just heard myself say 'd'you hear that.' All I've got to do is not say it, right?"

"Sure." But he said it like he was only indulging her. "Simple as that. Peek into the future, rewrite the timeline, go for tea. I do it all the time."

"You are so full of it," her reflection said.

"Hah!" she declared. "That's right! D'you hear that?"

He just grinned at her, and only then did she realize what she'd said. "Oh, that's not fair!" she complained. And there, look, she was still doing it.

"Prove it, then," her reflection was saying now.

He shrugged. "You can see the past too; doesn't mean you can change it."

"But you can," she pointed out. Her reflection disappeared suddenly, and something occurred to her. "Hey, what happens if you step in here? Can you change what you'll say?"

"Course I can," he said smugly. "Easy."

This time she knew she was going to say it, and she didn't even care. "You," she informed him, "are so full of it."

He didn't disagree, just smiled, and she shook her head.

"Prove it then," she told him. She stepped out of the silver sphere and tilted her head toward it. "Let's see you rewrite the timeline. Go on!"

"Got a better idea," he informed her. "Don't say I never bought you anything."

That was enough to distract her, even if he hadn't taken her hand and pulled her away from the glass ball thing. "Bought me what?" she wanted to know, skipping a little to keep up. "What are you going to buy me?"

"Wait and see," he said cheerfully. Maybe it was supposed to be mysterious, but he sounded like he was seconds away from laughing, so she kept at him for the fun of it.

"Come on, tell me," she insisted. "Is it... chips? Nah, this lot doesn't eat chips. Ice cream? Everyone eats ice cream. It's got to be a universal constant."

"It's not," he interrupted.

"Not a universal constant, or not what you're going to buy me?" she teased. "I haven't had ice cream in weeks!"

"Hold still," he said, squeezing her hand to warn her as they came to an abrupt stop. Other pedestrians--if you could call the things that weren't really walking pedestrians--swirled around them, except for a vaguely human-looking shape directly in front of them.

The doctor dropped her hand and pulled her closer, arm around her shoulder, and for a moment she thought it might dangerous. He was beaming at the still form, which didn't really mean anything. But he said "Smile!" instead of "Run!" and that had to be a good sign.

She smiled uncertainly at the human-like person, and the little colored box in its hands lit up with a blue glow. The blue light swirled all around it before fading, and then there was a sound like a ding and a piece of paper popped out of the box. "Compliments," the sort-of human said, offering the paper to the doctor.

"Right," the doctor agreed, letting go of her to accept the thing. "Thanks!"

"What is it?" she wanted to know, crowding close to him to peer at it. "What's that, a sort of photograph? Who is it?"

He passed it over to her, folding his arms as he turned to look over her shoulder. "Look closer," he said, sounding amused.

It was a couple of little kids, and now that she held it, she could tell it wasn't paper. It was some kind of filmy plastic or something. A little boy with his arm around a shorter blonde-haired girl, one grinning widely out of the frame and the other just smiling, a little warily, like she wasn't quite sure this was where she was supposed to be.

"Hang on," she said, frowning at the picture. "That looks a bit like me when I was little."

"Yeah," the doctor agreed. He was crowding her as he studied the image too. "Your hair's lighter now. And where'd you get that t-shirt? Not your color at all."

"That's my gym team shirt!" she exclaimed, lifting her head to stare at him. "I grew out of that when I was seven and my mum cut it up for rags."

"Seven?" He didn't return her look, pretending to scrutinize the picture more carefully. "Funny. I'd have said eight or nine."

"If that's me," she said firmly, "there's no way I'm nine. The gymnastics team got new shirts every year, and that's an under sevens tee."

"Oh, not you," he countered. He nodded at the picture. "I meant me."

She gaped at him, then twisted away from him to hold the picture up beside his face. She squinted, looking from the grinning little boy to him and back again. "Blimey, is that you?"

"You don't have to look so surprised," he said, sounding hurt. "I grew out of it."

"Is that you?" she repeated. She couldn't help giggling. The little boy had brown hair and bright blue eyes and an insanely pleased expression on his face, but... "It doesn't look anything like you!"

"Well, that was a long time ago," he said defensively.

She bit her lip, trying to hold in her grin. "Is that a school uniform you're wearing?"

He gave her a suspicious look. "How d'you know that?"

She laughed, delighted by absolutely everything. His expression, the little boy in the picture, the comment about her hair, all of it was suddenly perfect. "I know what you looked like when you were little!" she gloated, spinning away to keep the picture safe in case he tried to take it back. "I'm so keeping this!"

Instead of chasing her, he just watched her dance away with a smile on his face. She grinned back at him. "Is this my present, then?" Because she had to admit, it was a good one. Incomprehensible, but good.

"No," he said, surprising her. "Little further down. Less tourist-y."

She followed him without question, but when he paused in front of an open-air vendor's display she raised her eyebrows. The racks were filled with gadgets and charms and sparkly things that she couldn't see much purpose to, except that they were pretty and a lot of them seemed to have the same sorts of symbols on them. Like... souvenirs, or something.

This was definitely where he was going, though, because he was pulling something off of one of the racks and holding it up for the vendor to see. She squinted at it, but the mud-like vendor person distracted her by waving him away. "Our compliments," it was saying, and when she looked at the doctor he was giving her a sideways glance that she didn't think she was supposed to notice.

"Well," he said, looking decidedly uncomfortable. Like he wanted to argue, but wasn't about to do it while she was watching. "Thanks, then."

The same thing the sort-of human with the camera had told him, she thought, making the connection abruptly. Was he getting things he shouldn't for free? Or was she totally misreading the situation?

"Here's your present," he told her. He was holding up a little silver charm in the shape of the letters "TT". The same design was repeated all over one of the racks, obviously some kind of identifying symbol, and he was waiting for her reaction.

"Sorry," she said innocently, "did you say not tourist-y?" She was glad to see his face relax a little with the teasing. "Or did I hear you wrong?"

"I said less tourist-y," he corrected, fingering the charm and then holding it higher so it was on a level with her face. "Say your name."

She was already leaning closer to inspect it. She gave him an odd look, but she said obediently, "Rose Tyler."

He spun the charm around in his fingers, held it to his ear, and then nodded in satisfaction. "All set," he declared. "C'mere. Goes on your zipper."

She stared at him in utter non-comprehension. When he reached for her, though, she came closer and let him take hold of the edge of her sweatshirt. "Can't have you taking it off and leaving it somewhere," he explained, fussing with the zipper.

She opened her mouth to protest that she didn't, but he overrode her. "You do," he said, eyeing her until she subsided with a token sigh. "All the time, it's just luck you haven't lost it yet. This way, anyone who travels finds it and they'll know to bring it here."

"And by 'travels' you mean 'travels in time,'" she guessed, watching him affix the little "TT" symbol to her sweatshirt zipper.

"Only kind that counts," he agreed, a little less cheery and a little more concentrated as he gave the zipper a tug and the thing didn't come off. "And even if they don't, at least they'll have your name."

She frowned at him, wondering where that came from. "How d'you mean?"

"Touch it," he suggested. He took a step back, folding his arms again and looking expectant.

So she took hold of the new zipper pull, and as soon as she touched it she heard her own voice saying, "Rose Tyler." She blinked. "Well, that might get some attention."

"Only person who hears it is the person who touched it," he told her. "Very low-key, very subtle. Don't leave your sweatshirt lying around and no one'll ever know."

She made a face at him, but he was staring over her shoulder like he'd seen her mum or something. She turned. Nothing weird behind her--at least, nothing weirder than everything they'd seen since they got here. "What is it?" she asked, scanning the street for some clue.

She heard him whisper something that didn't make any sense. Before she knew it, he was off at a run and drawing every eye in the crowd with his yell. She knew when to leg it. She was right behind him as he chased whatever it was she hadn't seen, and people were actually getting out of their way, but they must not be catching up with his wild goose because finally he turned a corner and just stopped.

She ran into him, bouncing off of his shoulder and gasping for breath. "Oi," she panted, "what was that?" She drew in another breath and added, "Trouble?"

"Yeah," he said, staring down the crowded street. He didn't explain, though, just muttered, "That pretty much sums it up."

"Trouble," she reminded him breathlessly, "describes everything we've ever done."

He favored her with a half-smile, like he wanted to be amused but couldn't quite manage it right now. "Think I just saw a dead person."

The thing about Siberia was that it had stabilized long before anyone moved in and started selling souvenirs. It was a self-regulating temporal anomaly, something everyone was willing to take advantage of but not many people could completely explain. Come here, and you could meet anyone from any time--but you never met them before you'd met them the last time, and you never met yourself.

Temporal enforcers loved it, because they could catch up with friends in their off-hours without having to use company resources. Tourists came in droves, enjoying the company and the freedom from "native" time restrictions. Physicists studied the environment, social scientists studied the community, and all the smart ones--students, mostly--gave up and got drunk already.

Siberia was not for the logical mind. It was for the curious ones, the wanderers, the people who were willing to accept the possibility of anything they could perceive and a good number of the things they couldn't. It was for the minds whose first trip through time had taught them that everything they learned in school was wrong.

The Time Lords rarely left Gallifrey, and those that did were not the most logical his world had produced. They had all found their way here at least once in their lives. And if there was any place in the universe that still remembered them, Siberia was that place.

Memories were all they were, though, at least for him. The last time he'd seen anyone from his planet had been just before the battle that wiped them from the face of the universe. You couldn't see a person before you'd last seen them, even here.

So the girl with the braid and the black bomber jacket was a figment of his imagination. She had to be. She was just a memory, a time ghost, a trick of the temporal anomaly.

Or else he was going mad.