a/n: This is a story that I am writing as an early birthday gift for my good friend, bittie752. It was intended as a short one-shot, but as is usual for my stories, it seems to be growing longer than I planned. It will either be two or possibly three chapters.

Happy Birthday, Bittie.

Risking a Paradox

Chapter One

The twelfth Doctor walked around the console, slowly flipping a switch here and pressing a button there to program in the coordinates to their next destination. There was no hurry; as was typical of most of the people he traveled with, Clara wasn't ready yet. None of his companions had ever been prompt, except Adric possibly, and the Doctor would have been surprised if Clara had been ready. In her defense, part of the reason for her tardiness was that the TARDIS still didn't like her, didn't care for the impossibility of her existence; it would take anyone a while to get dressed if her wardrobe was continually locked or if the door to her en suite disappeared periodically without warning.

His mouth quirked into a small smile, one he immediately forced off his face. No, it was not funny, he told himself. After all Clara had done for him, he should be more sympathetic. He really needed to talk to the TARDIS about how she treated Clara. And he would. Eventually.

He reached across the console to spin a dial that controlled the speed of materialization—he thought—when he got a crick in his neck. Wincing, he stopped to rub it, and then stretched his back. It hadn't been all that long since he had regenerated, and this was the oldest body he had had in centuries. He wasn't used to it yet, not to its weight or height or how it ached occasionally now. Still, it wasn't the worst body he had ever had, nor was it the oldest. He'd get used to it, just like he had all the others. The chin wasn't bad in this one, nor were the ears, and the eyebrows were certainly an improvement over his last body. And the hair… oh, the hair he quite liked. No, it wasn't ginger, and that had been a huge disappointment, but it was nice and thick and he thought the smattering of silver in his hair suited him, particularly after all he had been through. It, together with the lines on his face, gave him a gravitas that he didn't quite have in his last incarnation.

He ran a hand over his hair, smoothing it down a bit, and for a moment he wondered again if Rose would have liked it. That was one of the first things he had thought about when he had seen himself in a mirror for the first time after regenerating. She had really liked the hair his tenth body had had, and with good reason. Even he had to admit that that him had had really great hair. But he preferred himself this way. He always did. Every incarnation preferred himself over the previous ones. He just was disappointed that he'd never know what Rose thought.

He found thinking of Rose wasn't as painful as it had been. Oh, it still hurt a bit, and he still missed her every single day, but it wasn't the gaping wound it had been in his tenth life and during a great deal of his eleventh. But at times like these, when something big had happened in his life, and what was bigger than a regeneration after all, he wished she were still there to talk to, to joke with, to hold hands with.

Even after centuries, his hand felt so empty.

"That's not what you're wearing, is it?"

He turned to see Clara standing in the doorway, her arms crossed and her head tilted to one side. She had her lips pressed together disapprovingly.

"Of course it's what I'm wearing," he said crossly. "You can see that I'm wearing it. I'm standing right in front of you."

"I thought we had talked about this." She tapped her toe and looked at him pointedly. For a moment he was reminded of her governess persona. All she needed was a long Victorian gown and a feathery cap instead of the very short dress and knee high boots she was wearing. She must have gotten her wardrobe open, he thought absently.

He scowled at her.

"There is nothing wrong with what I'm wearing. And it's certainly better than what I have chosen to wear before."

"Which time?" she asked. "Because if you mean when you were in your sixth body, I'd have to agree with you."

His mouth twitched. "No. No striped lemon-yellow pants, no jacket that resembles a patchwork quilt, no floppy, polka-dotted bowtie… No bowtie at all, actually."

Her mouth twisted into a small, teasing grin. "You used to say that bowties were cool."

He shuddered and made a face. "What on Earth could I have been thinking?"

"That's what I wondered at first," she said dryly. "And then I decided that you weren't."

He shot her a look before turning back to face the console.

"So where are we headed now?" she asked.

Clara's boots clicked on the floor as she walked across the console room and down the stairs to join him. The Doctor was staring thoughtfully into the glowing display screen that was built into the console. She looked curiously at it, trying to understand what he saw in it, but as usual it told her nothing. It was filled with the circles, triangles and other geometric shapes that formed the Doctor's written language and that only he could read.

He paused for a moment, and then he quickly began to reset all the dials he had adjusted earlier. "I think I'll set it at random," he told her. "I haven't done that for a while. Well, at least not in this body." He reached over to another section of the console and flipped a few additional switches.

A worried look crossed her face. "Doctor, are you sure that's a good idea? Every time you've done that in the past it has ended up in a disaster."

"Not every time," he countered.

She opened her mouth to argue, but before she could come up with a rejoinder the TARDIS began to make its familiar wheezing and groaning noises. They ended with a loud thud.

"Oh, look. We've arrived already," he said. "Shall we go see where we are?"

Clara was extremely tempted. The Doctor and danger went hand in hand, but there was so much to see out there in the universe. That's part of the reason why she was with him, after all, to walk on new ground, see new stars, meet new people… She bit her lower lip and glanced at the door before looking back at him.

"Or you could stay here while I go," he suggested with a shrug. "Suit yourself."

She looked at the door again and her curiosity got the best of her.

"Oh, all right," she said with a deep sigh. Decision made, she crossed the room purposefully, flung open the doors and stepped outside.

The TARDIS had landed in a deserted alley between two tall buildings which appeared to contain flats. Although the Doctor and Clara stood in the shadows, overhead the sky was a bright blue, and the distant sound of children laughing filled the air. She nodded her head decisively.

"So far, so good," she said. "So we're obviously on a planet, rather than a ship or a space station or something, and it's one similar to Earth. Bright, sunny day, not too warm, not too cool… What do you think, Doctor? Where are we?"

She turned to the Doctor. He stood motionless for a moment, a look of shock on his face. Wordlessly he strode away from her and rounded a corner, disappearing from view. This was so totally unlike him, she thought. He had always liked to impress her with his vast knowledge of everywhere they went, even after he had changed, and he obviously knew where they were. Why wasn't he trying to show off? Clara followed him, her brow furrowed in puzzlement.

As she rounded the corner, she almost bumped into him. He stood frozen, all coiled tension, looking at a park that lay directly ahead. Its adjacent playground was full of children.

The Doctor stared intently across the wide expanse of grass. On the far edge of the park stood two people, a young blonde woman and a man who appeared slightly older than she did, who were deep in conversation. The man, who was wearing a brown pinstriped suit and who had artfully messy brown hair, was pulling on one of his ears, while the woman, in jeans and a bright pink top with her hair in a tiny ponytail, stood with her arms folded in front of her. Even though he couldn't see it from where he stood, the Doctor knew she was frowning.

Thankfully Clara hadn't noticed the two on the other side of the park, he thought. He needed to deal with the situation before a paradox was created, and preferably without Clara knowing. Not that Clara knowing would be a crisis. He just wanted to handle it without her getting involved.

He and Clara really ought to just get into the TARDIS and leave, but he couldn't bring himself to do it.

"Doctor, what is it?" she asked.

"Clara, find out where, or specifically when, we are," he said, still watching the pair on the other side of the park. He already knew exactly where and when they were, but sending her away to find out would keep her busy for a while. Hopefully.

"How…"

"There's a newsagent back the way we came." A tone of mild irritation had crept into his voice. "Go look there."

Clara opened her mouth to speak, and then thought better of it. She had learned in the short time she had spent traveling with this Doctor that there were some times that it did no good to argue with him. But that wasn't to say that she couldn't let him know how she felt. With a huff of exasperation that she knew he heard, even though he didn't acknowledge it, she turned and walked back in the direction of the TARDIS.

Once the Doctor was certain she had gone, he slowly crossed the grass that lay in front of him. The man, his Tenth self, had left, headed to his TARDIS he remembered. Rose, on the other hand, for of course it was Rose, had gone the opposite direction and had sat down on a bench near the playground to watch the children.

This was a bad idea. It would only serve to open old wounds. Wounds, he realized, that weren't nearly as healed as he had thought. He shouldn't do this, he told himself. He should return to the TARDIS and leave immediately. But he had never seen her with these eyes before, and the temptation to see her again was too great. Entirely unable to stop himself, he continued forward.

Why, of all the possible places and times in the universe the TARDIS could have landed them, had she chosen here?

And then his mind returned to something the TARDIS had said when she was in the form of Idris.

"You don't always take me where I want to go," he whispered, "but you always take me where I need to go."

But why on Earth did he need to come here?

When he reached the bench where she sat, he saw she was sitting quietly, staring ahead of her at nothing in particular. Her shoulders were a bit slumped and her face held an unreadable expression. He sat down on the same bench, careful to sit as far from her as was possible. He longed to sit next to her, to put his arm around her and pull her into his side as he had so many times in the past, but he knew he couldn't. Even sitting this close to her was a risk, but a relatively minor one. Although he knew her, she didn't know him; he was just an older man, a stranger, sitting on the park bench near her.

And he couldn't resist one last time being near her.

Rose glanced out of the corner of her eye at the man that had sat down next to her. Much older than she was, much older than her mother, in fact, she had seen him emerge from the alley accompanied by a very pretty young woman with long dark hair. Probably his daughter, she thought, and perhaps he had grandchildren playing on the play equipment in front of him. That was nice. She really hadn't known her grandparents all that well, and she didn't think they had ever accompanied her to a park.

The Doctor glanced at her… and she caught him at it. To his relief, she smiled at him. No, it wasn't her tongue-touched flirtatious grin she used to use with him, but it was a smile.

"Hello," she said.

"Hello," he replied, smiling back. He forced himself not to make it an all-out grin.

They both turned back to watch the playground. After a few moments she turned back to him.

"I'm Rose, Rose Tyler."

He hesitated for no more than a split second as he ran through all the names he had used while they had been traveling together. He had used most of the names of his male companions around her at one point or another… "Harry," he answered as he turned to face her. "Harry Sullivan."

"Nice to meet you, Harry."

Rose thrust out her hand at him. After a moment's hesitation, he moved closer to shake it.

"The pleasure is all mine, Rose," he replied.

When he took her hand, Rose felt a jolt of… something. Almost a shock of recognition, but that wasn't possible, was it? She didn't know him. And he certainly wasn't from the Powell Estate, not with his accent. She couldn't quite place it, but it was certainly more posh than everyone else around here. She peered at him.

"I'm sorry, but do I know you?" she asked.

His hearts rate shot up, but he didn't allow it to reflect in his expression. "I don't think so. Why?"

"'S just, you seem familiar somehow," she said. She shook her head as if to shake the thought out of her mind. "'S probably nothing."

The Doctor smiled again and then forced himself to turn away. This was not good. He shouldn't be here, he shouldn't have let her see him, and he certainly shouldn't be talking to her. But it had never occurred to him that she could recognize him on some level. Well, his Rose had always been extraordinary. He extended his Time Sense to try to determine if there had been any damage to the timelines. Seeing his own was difficult but not impossible, and he seemed to have a better talent for it in this body than in most of his others. After scanning it for damage, inwardly he breathed a sigh of relief. Thankfully, there had been none.

So far, a little voice inside his head said.

Rose turned back to watching the children. The TARDIS had been damaged during their recent trip through the Void. The Doctor was off trying to repair her, and she knew she'd just get in his way. And she didn't want to go back to her mum's flat; after a couple of days of being back on the estate, her mother was driving her spare. She was only sitting in the park because she had nowhere else to go now that Mickey was gone.

After a moment she turned back to her bench mate.

"So that girl you were with, was she your daughter?"

"Who, Clara?" he asked, turning back to her. He was surprised. He hadn't thought she'd noticed them when they'd emerged from the alley. "No, she's not my daughter. She's just a friend."

"Oh." She smirked. "I've heard that before."

He blinked and hurriedly shook his head. "No. It's nothing like that."

"'S alright, y'know," she said. "'S a bit of an age gap, but I've known bigger ones."

He snorted. Maybe not bigger, but close to, he thought. "No, really. She's just a friend."

She smiled disbelievingly and turned back to the playground. He should really go, he told himself again.

After a moment her smile faded. He knew that expression on her face. She wasn't just thoughtful; she was sad. And if there were anything he couldn't bear, it was seeing Rose Tyler sad.

"I'm sorry if this is a bit forward, and you certainly don't have to answer, but is everything alright?"

She bit her lip and crossed her arms, hugging herself.

"Yeah, 'm fine," Rose answered, turning towards him again. To her surprise, he looked genuinely concerned. What the hell, she thought. She needed to talk, and she couldn't talk to the Doctor or her mum. And there was no one else, not anymore. Maybe it would be good to talk to a stranger, get some perspective from someone who didn't know her and didn't know the situation or the people involved. She moved a little closer to him to talk a bit more privately.

"No, 'm not fine," she corrected herself. "Things have just been a bit tough recently, y'know?"

"Does it have anything to do with that boyfriend of yours?" he asked. She looked puzzled. "The man you were with. I saw you talking to him earlier."

"Oh, no, we're not like that," she said. "He's just a friend."

"Really?" He raised his eyebrows. "You could have fooled me. I saw the way he looked at you."

Rose shook her head. "Nah, he doesn't think of me that way. At one time I thought… well, let's just say I found out the hard way I was wrong. But that's fine," she said hurriedly. "'S just, we went through some tough times. Me an' him and another friend of mine were travelin' together, and some really bad things happened."

She was being purposefully vague because how on Earth could she explain to Harry that the man he had seen her talking to had left her and Mickey on a spaceship in the far future not once but twice: once to attend a party while they almost get killed by clockwork robots, and the second to jump through a time window—on a horse no less—with no plan on how he would return to them. And then immediately after that how they had gotten stuck in a parallel universe only to see her parallel mum get killed and her parallel dad reject her? Harry'd think she needed to be sectioned.

"Anyway," she continued, "my other friend, Mickey, his name is Mickey, he stayed behind. We've known each other forever, and I'm not gonna ever see him again." She drew in a ragged breath and jerked her head in the direction of the TARDIS. "And he doesn't seem to care."

She was horrified to find her eyes well up with tears. She sniffed, trying not to cry, and turned away. "You don't need to hear about all this," she said.

"Rose."

She turned back to him to find he had moved a bit closer to her again and was holding out an old fashioned handkerchief. She took it gratefully and dabbed at her eyes. "'M sorry. I'm a bit of a mess."

"It's alright to cry if you need to," he said gently. "And I'm sure he does care; I bet he just doesn't know how to express it."

She rolled her eyes and chuckled a little. "Yeah, that'd be him all over."

He smiled in response, until he heard what she said next.

"Anyway, he's gonna wanna go again, and I'm just not sure I can go with this time."

His hearts skipped a beat and he felt a chill run down his spine.

"'S just, I need a break, yeah?" she continued, returning to looking in front of her. "But if I don't go with him, I don't think I'll ever see him again either. He's not one for comin' back." She took a deep breath. "But maybe I'll just have to risk it."

He stared at her with a look akin to horror. He had known she had thought about leaving after the business with Sarah Jane and then again after Reinette. But how had he not known she felt this way after their foray into Pete's World? But she didn't leave him, he told himself.

Just to be safe, he checked the timelines again and was shocked to find that the line, which had been firm when they had begun talking, was now softening. If it continued like this it would go into full flux, and then no one, not even he, could predict what would happen.

She could leave.

But would that be such a bad thing? If she left him, the old him, perhaps she'd never be trapped in Pete's World.

But she wouldn't be with him, he reminded himself. And she wouldn't be with his meta-crisis self either. The thought of her happy in the parallel universe with his other, part human self sometimes had been all that sustained him through times of despair.

"Have you tried talking to your friend about this?" he asked carefully.

"Not really," she answered. "He doesn't do feelings very well. 'S a bit too domestic for him, if you know what I mean."

"I think so," he replied ruefully. And when she turned to face him, he grinned at her.

His smile took years off, and Rose wondered to herself if somehow she had misjudged his age. Some people looked older than they were, others looked far younger. The Doctor was one of the second, but of course he was a special case. Who else was almost a thousand years old yet looked like he was barely out of his twenties? With his sharp features, greying hair and lined face, she had assumed Harry was older than her father would be if he had lived, but maybe he wasn't. Perhaps he was one of those who was younger than he looked. Either way, young or old, he had a wonderful smile. It lit up his entire face. He was really quite handsome, she realized, particularly when he smiled.

Once again she was struck with the sense that she knew him somehow. No, she had never seen him before, she was sure of that. His features were a bit too distinctive, too memorable, for her to have forgotten him. But there was something about his smile. And his eyes. If his smile made him look younger than he was, his steely blue eyes made him look far older. They reminded her of the Doctor's eyes, particularly her first Doctor; his eyes looked as if he had traveled too far and had seen too much, and as if he had the wisdom of the universe behind them.

She stared at him, and his smile faded as he met her gaze. Even after crying, she was breathtaking, he thought; the sunlight caught in her light blonde hair, making it appear to almost glow, and her flawless skin was just slightly pink from their time sitting on the bench in the sun. And how could he possibly have forgotten how beautiful her eyes were? Because they were: whiskey-colored with flecks of gold that made him recall her time as Bad Wolf.

He took a deep breath and looked away for a moment. Before he did something incredibly stupid, he thought, he needed to leave. Now.

But he didn't.

Instead, he turned back to her. "If you want my advice, which you probably don't," he said with a wink, "you should go talk to him. He just might surprise you."

"I doubt it," she replied. "But you're right. I should at least go talk to him. I mean, what's the worst he could do? Kick me off the TAR—I mean, kick me to the kerb? I was thinkin' about leavin' anyway." She grinned at him. "Actually, talkin' to you has really helped. I feel a lot better. Thank you." And she leaned forward to kiss him on the cheek.

And then something happened that Rose would have sworn only happened in the movies. At that very moment he moved. They both froze and stared at each other wide-eyed as her lips met his. She should pull away, she thought. She didn't do this, kiss random strangers in the park of the estate. What would he think of her? Any moment now he would pull away and she would be even more embarrassed than she had been earlier.

But he wasn't pulling away.

Instead his eyes closed and his lips softened under hers. And instead of pulling away, she closed her eyes and leaned closer.

It was soft and sweet and gentle and over far too soon. When he finally did pull away, she opened her eyes to find him staring at her, a look of longing on his face. It should have scared her, for someone who was basically a stranger to look at her like that, but it didn't. And then all of a sudden she knew.

"Doctor?" she whispered.

"Hello, Rose," he answered.