Title: Chemical Precursor
Rating: K+
Summary: Post PotW fic from my Doctor's point of view…as in the one I ended up with from the Chemistry series.
Disclaimer Funny, I don't own any of them…however, I suppose that this particular Doctor is mine…sort of. Maybe not…it'd stand up in court in the US…

A/N: This is, I suppose, a prequel to the Chemistry series, though, as a prequel, you don't have to have read them. It's from the Doctor's point of view, picking up straight after the end of PotW. Sounds like your typical PotW, post-regen fic. Probably is. But this Doctor is based very much in the one developed in the Chemistry series. Anyway, I'm crapping on. I hope you all like it and thanks once again to my wonderful, wonderful beta saganamidreams. Who has brought out her own brilliant, brilliant fic called Sojourn which is just brilliant…and can be found here

On with the fic…

She'd run from him so fast he hadn't even managed to get a word out, but that was partially due to the teeth. He had no idea where she'd run to. She wasn't in her bedroom or the kitchen and other than that he didn't really know where to look. Perhaps the old him would have been able to work it out; he'd had the time to factor her eccentricities and intricacies into his way of thinking. He knew how she thought, knew her.

But he was new, the atoms were the same, but every single one had been pulled apart and then shoved back together; new configurations, new orders, large chunks moved around until nothing felt the same. That included the way his mind worked, the way it understood things.

He still knew about Rose, but he didn't know her. He knew how he used to feel, but it was a memory, not a reality. It was strange, in a way, that her shock still managed to upset him, that his inability to find and comfort her still made him angry. These were the reactions of the old him, he didn't know why he still had them.

But no, he couldn't find her, couldn't even manage to look for her, so instead he went back to his own room. Throwing a lingering gaze over it, he was saddened at the loss. Not of his old self but what he'd had; with Rose, with life.

Stooping, still feeling awkward and off balance, he began to remove the mess. The jumpers that no longer appealed, the boots that wouldn't fit and the jacket that would cause him almost as much hurt as it would cause Rose should he ever again wear it. In the end, he was left standing, shoeless and jacketless, in an empty room, everything had been shoved into the back of the closet, hidden from sight.

Then he walked out, finally finding a stride that worked for his new legs. Needing to see himself, to see what Rose had seen and to fix it, he headed for the wardrobe.

What he hadn't realized was what the wardrobe had become: Rose's and Jack's, their camaraderie leaking itself into every corner of the room, their casualness meaning that clothes were thrown around and empty chairs were still huddled in conspiracy.

He didn't usually go here. All his clothes were kept in his own room. But now he needed a change. Walking to the large double doors, hands trembling as his fingers played over the soft cotton of one of Rose's favorite T-shirts strewn over the back of a chair, he silently hoped.

Technically, it was the TARDIS's choice; she'd offer him what she knew he needed. He could always ignore her, shut the wardrobe and open it until he found what he wanted, but it was tradition, sort of. He remembered all the other times he'd done it; this time was different.

Opening the doors, he faced his future. Brown pinstripe suit, strangely enticing, the white cotton shirt and the dark tie making his eyes crinkle as he imagined how it would work. Next to them: a long brown coat. He reached out to find it soft under his fingers; he liked it, it would work nicely.

Pulling the garments from their coat hangers, he noticed a final offering, nestled between the browns: a white lab coat. That made his lips twitch up despite the fact he knew perfectly well that the day before he'd been utterly against all types of science. He glanced up at the high domed ceiling, smiling at his ship, his constant, inescapable conscience.

Stripping off the slightly oversized jumper and the black jeans that felt itchy against his skin, he eagerly slipped into his new look. Only when he was happy it was all on right, comfortable with the soft materials, did he turn to the full length mirror.

He took himself in, not admiring or complaining, just trying to calculate Rose's reaction; if him changing clothes was good or bad, if so drastic a change with the hair and the eyes was for better of worse. He wasn't sure, but he admitted that he liked it.

His bare feet caught his attention. Big feet, much bigger than they used to be, and, while he was all for trying to save the world in a suit with his long jacket trailing in the wind behind him, he was not about to try doing it barefoot.

Looking back at the wardrobe, he saw what he was expected to wear. White trainers. On closer inspection, white All Star Chucks trainers with the blue and red lines around the sole. His brow creased, everything else felt perfectly in tune but this didn't.

It felt suitable, felt like it matched the rest of him, but it wouldn't have been his choice, had he been given one. Still, what difference did a pair of shoes make, and they weren't bad. He sat on the nearest chair and slipped them on over white socks, tying the laces up tight and then glancing at his reflection in the mirror.

A particular smell, a memory that suddenly became a reality, crept into his mind. He angled his head and saw another of Rose's shirts on the back of the chair he was sitting on. Ethyl methanoate, his mind prompted unbidden. That's what she smelt like; he'd spent so many hours trying to work it out with his old logic, his old mind, trying to find something that matched up with her scent and now, just the tiniest whiff and he knew. Ethyl methanoate: raspberries with the subtlest hint of rum.

He caught site of movement in the mirror as his eyes refocused. Turning around in his chair, he called out to her, making her stop. "Rose."

Now what was he supposed to do. "Hi." Oh, yeah that's a fantastic opening line, please, put more emphasis on the fact you're a completely new person.

She just stared at him, confused and upset. Feeling his breath catch at her pain, again surprised he cared so much about a memory who was only slowly working her way into reality, he tried again. "I'm sorry."

"For what?" she spat back.

Okay, that was anger; she was angry and, if he was fair, she had every right to be. Thinking hard, he answered, "For not telling you sooner."

She breathed deeply and he could tell she was trying to stop herself from falling apart. "What even happened?"

"It's called a regeneration -"

She cut across him. "But why?"

"You still don't remember?" he asked, half glad half not at that fact.

She shook her head, eyes glassy with unshed tears. How could he tell her? What could he tell her? He held her eyes, not wanting to but having to. "You saved the universe."

Startled, than angry again. "Then why aren't I dead?" It was a shout, but he could see the pain she was trying to cover with violence.

How to tell her?

"Because I saved you." He could feel himself trembling, his jaw clenched, his stomach tight and the loss rising in his throat. He'd lost her and now he was going to lose her again. She'd leave. Inevitably.

"You saved me?" Calmer now, quiet and tentative, like she was trying new words on.

He nodded, unable to speak for the tightness in his throat. Life wasn't fair. It would take her from him again. But he didn't regret it. He'd do it all again, the pain, the loss, the death, even knowing she'd leave him at the end of it. Go back home, wanting to be with him but not him.

"You're still you then?"

"No. I'm different." The words were wrenched from him, the debate lasting a second, choosing between two options all too easily: whether to lie, to act as best he could as the person he'd been the day before, the person she wanted. To pretend forever just knowing she would always be there if he did. Or the truth, telling her so much of the old him was completely gone, replaced by new ideas, new passions and new fears.

He'd never be able to lie to her.

A shaky breath but she refused to cry. "Your clothes…" she trailed off. She wasn't ready to leave but she wasn't ready to accept it. He was too new, nothing familiar. Not yet.

He faltered, glancing down, suddenly unsure his new self, his clothes, his hair, his eyes, so utterly different, were right. Perhaps he should have cut his hair and kept the jacket. No. "I need to be me. The new me."

Once again, she dragged a breath from the air around her; his answer, while true, wasn't what she wanted to hear.

"But it's not…" she paused and he knew she wanted to say 'you' but had realized it made no sense. He wished and feared that she'd leave any second. "It's all too new. Unfamiliar. I don't think…" she trailed off again. Eyes slipping away from his to the floor, forcing him to wait for the unavoidable conclusion.

Wait for her to continue: I don't think I can stay here. I don't think I want to be here. I want to go home. Never see you again.

For once, he wouldn't argue, wouldn't make it harder.

"Where'd you get the shoes?" she asked suddenly, aspects he recognized from the memories joining reality: curiosity, wonder, confusion.

He glared downwards; he knew the shoes had been wrong. "The TARDIS chose them," he answered, his voice finding control as the pain ebbed into a faint throb, his attention elsewhere.

Moving towards him, he tensed, what did she want? She bent down, eventually ending up on her knees, staring at his feet. "What?" he question, utterly bemused. Her tears had vanished for the moment. His were gone too.

"They're familiar," she explained.

He looked at them. They were dirty, worn, used. Nothing like the rest of his outfit. How peculiar. She glanced up, her eyes searching out his, fear and wariness clouding with her continuous exuberance to learn everything. Using her hand, she angled it around and pulled his pant leg up until she found what she was looking for. A plastic circle with a star and the brand name. Her brow creased and she stared back up at him.

"Where'd you get these from?"

Starting to feel uncomfortable with the conversation, obviously something was wrong, he insisted, "I told you, the TARDIS put them in the wardrobe for me. Just like she chooses the clothes she thinks you'd want."

"And you want these?" she shot back, voice increasingly suspicious.

"No. These were strange to begin with."

She moved back, still kneeling in front of him. "They're mine."

"What?"

"Look," she pointed out a tiny gold 'RT' painted over the star. "They're mine."

"They can't be yours," he said defiantly, but inside he knew perfectly well what the TARDIS was capable of, he just didn't know why.

Rose grinned, really smiled, properly with her teeth and her tongue catching between them. The wariness was gone, just a light teasing, a memory suddenly become real. "I know that, your feet are much too big."

He looked down, a little put out but treasuring the newness she presented. "So?" he asked, hopeful but still in doubt.

"So," Rose said, voice strong and untainted, decided. There was no going back on what she said. "She's trying to make it easier for us. The TARDIS." Rose brushed a hand over the metal floor she sat on. "I trust her."

Gobsmacked, he smiled back. "You're staying?"

She nodded, slowly at first but increasingly defiant.

A manic grin, Rose watched. Honest, and pure, nothing like what it would have been the day before. It was an idea becoming a reality before her eyes. But different. Likable despite being different.

He stood up and offered her his hand. Without hesitation, she grasped it, hands fitting perfectly, fingers entwining with his, just because they always would, no matter what, and she pulled herself up.

As they walked out the door, they didn't let go.