The Doctor woke, warm and comfortable, in a human bed, in human pyjamas wrapped around a human girl. Except wait, no... no no no no. She couldn't have! The Doctor sat bolt upright and looked into the face of his sleeping companion. Hardly knowing what to hope, he grabbed the stethoscope on the bedside table (and what was a stethoscope doing there, anyways? Jackie Tyler as a doctor was terrifying. And, come to think of it, how had he gotten into these pyjamas? They wouldn't do at all; he was thinking something a bit more refined this incarnation...) and listened to Rose's heart... and heard an echo. Moving the stethoscope to the other side of her chest, he held his breath and heard a second heart.

Oh Rose.

For a moment, he was breathless at the thought of another Time Lord, a companion who wouldn't fade away with time. And that it was Rose, beautiful, brilliant Rose... Except it wasn't Rose, not really. The girl sleeping beside him was a fairytale, a pipedream and he wanted his Rose, his human Rose, back.

Shaking off the tempting futures his mind provided, the Doctor leapt to his feet and ran to the TARDIS, ignoring Jackie's indignant shouts. If Rose had done what he suspected she'd done... He flung open the door to see the tell-tale helmet hanging from the ceiling.

"What did you do?" He asked the TARDIS sternly. The ship responded in his mind, sounding like a small child bringing home a stray: a little sheepish, but oh please, oh please can we keep her? He sighed. An intelligent ship was all well and good in some situations, but this was taking it a little too far.

"You know we can't. It's not fair to Rose, or to her family. I know you miss them, me too, but we can't." He tried unsuccessfully to pry the watch out of the helmet. "Give me the watch. Please."

It came loose in his hand, accompanied by what he could only interpret as a telepathic pout.

"Thank you."

oO*Oo

He ran back to the Tyler flat, only to be stopped by an irate Jackie.

Slap!

"What the hell did you do to my daughter, you bloody great alien? I listened to her heartbeat, you know! She has two hearts; I heard 'em, loud and clear. And then what was I supposed to do? Couldn't take her to the hospital, could I? If you don't fix this, I'm gonna kill you."

Straightening, still clutching the side of his face, the Doctor held up the silver watch.

"Your daughter is in here; it's a long story, but essentially she became a Time Lady so she could come back, well forward, and save me, save the planet, actually. Still don't know exactly how she did that last bit really... I was dying at the time, so it's a bit fuzzy."

Jackie stared. "My daughter's in a pocket watch? And there's an alien in her body?"

"More or less. It's more complicated than that, but –"

Slap!

"Fix her. Now."

oO*Oo

"But I remember it. Gallifrey, and the schism and the laboratory. And you." Rose stared, wide-eyed at her new Doctor. "I... imagined it all?"

The Doctor sighed. "Not exactly. The TARDIS used what she knows to build you a Time Lord identity. Um... she rather, er, hoped that you would remain changed for a bit longer. Well, much longer. Well, forever, really. Anyways, in that hope, she built you a very detailed, very sustainable back story. She also gave you some of her essence, somehow. She actually managed to transfer, via the chameleon circuit might I add, a small part of the Time Vortex into you. Come to think of it, you should be dead – no mortal body is meant to take that on."

He stared searchingly into her face for a moment before his face took on a solemn cast.

" And I'm sorry. I'm so, so sorry, but you're not real, and there's a human girl, a real human girl, trapped in this watch, who doesn't know what's happened to her. You have to open the watch and let her out."

When Rose spoke, after a long moment of silence, her voice was high, like human Rose's was when she was trying not to cry.

"But I... I love you."

The Doctor's breath caught abruptly. It would be so easy, even now, to let her stay like this. But he couldn't do that to human Rose, nor even to Jackie and Mickey.

"I can't love you, I'm sorry, but I can't. If things were different, maybe I could have – but you are a fantasy, a tempting illusion, nothing more.

"This is all I can give you."

Cradling her head in his hands, the Doctor leaned forward to press a kiss to her lips. He let her sustain the contact until she pulled away to smile weakly at him.

She kept her eyes locked on his as her fingers slid over the silver watch's engraved surface, found the crack, and flipped the two halves apart.

oO*Oo

Rose, proper Rose, was back.

And then the Sycorax invaded.

oO*Oo

The Sycorax dealt with, (dealt with a little too well, actually, courtesy of Harriet Jones) the Doctor and Rose found themselves back in the TARDIS, sharing an awkward silence while the Doctor set new coordinates.

"So...how are you feeling?" Well, it seemed that this incarnation really couldn't stand silence.

"Strange. 'S like, I dunno, I was her, and I remember being her, but at the same time, she's this whole other person. Like, maybe, maybe how you feel when you regenerate?" Rose was silent a moment. "She did love you, Doctor."

He realised what Rose really meant (I love you) and recognised the opening she had created. Somewhere in his mind, he acknowledged that, no matter what kind of man he was, or had been or would be, he would love Rose Tyler. Fact. Still, she would leave him: by choice or by circumstance or by time and he would barely survive it as it was. He couldn't risk getting closer.

Disregarding, as he had so often done before, the opportunity to speak his mind on that particular topic, (actually, given the gob this version seemed to possess, he ought to take care not to blurt out his feelings in the middle of some technical explanation), the Doctor smiled.

"Quite right, too. Allons-y?"

Rose, sighed a little in defeat, but grinned her signature grin and nodded.

"Allons-y," she agreed.

He might not know exactly what the future held, but with this wonderful human by his side, he knew one thing.

It would be fantastic.

oO*Oo

I suppose that series 2 follows this without much AU, though Rose would still have at least some overly advanced knowledge. I was sort of trying to make this idea plausible while still setting up all the important plot developments. And adding in some gratuitous Doctor/Rose ship.