PAIRINGS: Rose/Yana, Rose/Lucy, Rose/Tish, Rose/Master (Simm), Rose/Ten

AUTHOR'S NOTES: This is an AU fic that diverges from canon during the end of Season 3. The first part of this fic, which is Rose/Yana and rated PG, is a fluffy sort of romp at the end of the universe that can definitely be read as a standalone if you don't like the darker stuff. If you intend to read the later three chapters of this fic, though, please take note of the high rating and the warnings which will be stated at the beginning of each chapter.

When the Dimension Cannon finally started working, Rose crossed her fingers and hoped that one press of a button would deliver her straight into the Doctor's arms.

Yeah, she grumbled. As if it was ever going to be that easy.

It could be worse, she supposed. The Dimension Cannon could have landed her at the beginning of the universe, before oxygen, where she'd have to hope the recall button worked quickly enough to pull her out of there before she suffocated. Or she could have ended up sometime a little further into Earth's history, though not far enough. It would be just her luck to get eaten by dinosaurs just as she was finally making progress in getting back to the Doctor.

Those were the sorts of risks she'd decided she was willing to take.

She wondered why the Cannon had brought her here in particular, though, where the stars were all gone, not just disappearing, and the last band of people seemed to be hiding from the ensuing darkness. Was it supposed to be a warning of what would come in both of her universes – all universes – if she didn't succeed? She knew that well enough without the practical demonstration, thanks.

Inside what the guards called 'the silo', it smelled like what Rose remembered of the slums of India from that time Torchwood had sent her there for a recovery mission; unwashed bodies in too much heat with too little space, and a hint of desperation adding spice to the rankness.

It made her sick, but not physically; she had a stronger stomach than that. Rose worried what would happen to those people if they couldn't be saved before the end arrived.

An odd blue creature that reminded her of the first alien other than the Doctor who'd really talked with her – she felt terrible that she couldn't remember the plumber's name anymore, but so much had happened since then – was the one who informed her that the hope these people clung to might not be in vain.

"Chan, there is a way out, tho. Chan, the professor is working on it every day, tho."

"The Professor?" Rose asked curiously. Chantho went off on a spiel so excited that Rose could barely follow the gist of it. There was some definite hero worship there. More than that, Rose was quick to realise. Chantho was clearly completely devoted to the man she spoke so gushingly about.

Rose had an inexplicable expectation that 'the Professor' might look like a cross between the Professor from Gilligan's Island and someone of Chantho's species (it was only later that Chantho told Rose she was the last of her kind, a reminder of a different alien which warmed Rose even more than the body heat of thousands of people packed together). It was a peculiar mental picture. The old man in his turn-of-the-20th-century get up seemed incredibly normal by comparison.

Rose could see why Chantho so clearly adored him. He was slightly arrogantly brilliant and slightly off, but with an openness about him that suggested the end of his universe hadn't burned him in quite the same way that the loss of Gallifrey had always so clearly marked the Doctor ever since Rose had known him. He was, in many ways, a lot like the Doctor had been in the last months she'd known him, when he'd seemed happier. It was hard not to like such a man, Rose found.

The Professor shook her hand so hard that she forgot for a moment that he was probably reaching the end of his life, hoping to hold on just a few more years, long enough to complete his work. In that moment, so happy to have someone new and seemingly interested in what he was doing to talk to, he acted more, like a puppy, fresh with enthusiasm.

Rose let his rough voice wash over her while her mind drifted.

This didn't seem to be anywhere near her own time. Rose realised that much from how the Professor spoke of times long since passed and knowledge forgotten which Rose didn't think had yet been discovered in the first place where she was from. Even in a parallel world, Rose couldn't imagine things being so much more advanced that they'd got to this stage of evolution before whatever was making the stars go out affected them. The Dimension Cannon, then, must have sent her off course. For all she knew, the only way the Cannon would let her enter a new universe might be right at the end of it, where the walls were somehow thinner. The Doctor would probably know better (or at least pretend to).

If this was the inevitable end of the universe rather than some mistake brought on billions of years too early like what was happening in the universe she'd found herself stuck in, Rose didn't think it was up to her to stop it, any more than the Doctor had jumped in to stop the Earth from roasting on their first trip out together. It had taken her a while, but she had eventually learned that some things just had their time.

She knew that she should call for another jump with the Cannon. She clearly wasn't in the right place, after all. The Doctor-tracking function she'd tried to rig up with the use of some of the odds and ends she'd had in her pocket that day she'd been stranded in the wrong universe clearly wasn't working yet, for there was no sign of him here. Rose wondered whether he'd ever travelled this far into the future, or whether he feared the unavoidability of people dying and leaving him behind to continue on alone too much to want to see this final struggle for life. Rose could only stand it because she could see the Professor's hope rather than just the possibility that it was ultimately futile.

Still, the Professor seemed to have any world-saving efforts pretty well in hand, anyway, from what Rose could tell. She should leave. She had other places to be.

She was so tired, though, having not been able to sleep a wink in the days since the Dimension Cannon had seemed to start working, far too jittery in the face of thoughts of that first jump. She just wanted to rest...

When she woke up, it took her a moment to remember where in the universe – or universes, she realised – she was. It probably didn't help that she didn't wake where she'd fallen asleep, perched on a tiny stool with her face pressed uncomfortably against the unyielding surface of the bench in front of her. The hammock-like structure that she was lying on swayed slightly under her as she swivelled around, looking for Chantho or the Professor.

The Professor was doddering around at the back of the room, her view of him partly obscured by all sorts of hanging bits of string and such.

"Up again, I see!" he exclaimed when he noticed that she was openly regarding him with curiosity. "Good! Good! Nothing like a quick recharge to get your mind going again, I say. Now, would you mind handing me that piece of equipment just by your head and to the left? No, no, the L-shaped metallic one. That's it. I usually have Chantho to help me with these things, you see, but she's due for her own sleep cycle. You don't mind, do you?"

"Um, no," Rose said, pushing herself off the hammock and making her way across the maze of clutter to the Professor's side. She placed the tool on the bench beside him. "Did you move me? While I was sleepin', I mean."

"Of course, of course," the Professor murmured, and Rose wasn't sure for a moment whether he was responding to her or having some kind of break through with... whatever it was that he was doing. Then he continued, "It was barely a moment's work. You, my dear, are not so heavy that even an old man like me can't shift you, and the bed was already made up. I use it when I want a quick kip, you see. Much more convenient than one of those silly little cubby holes out in the main living area that Chantho keeps trying to press me into when I'm a bit too run down to properly fight off her best intentions."

Rose reached out and placed a hand lightly on the Professor's arm. He stilled and looked up at her, giving her all of his attention suddenly instead of constantly trying to do seventeen things at once as he was clearly used to doing.

"Thank you," Rose said.

"Well, there's no point in a lovely young thing like yourself going and giving yourself a bad back so early in life," the Professor replied with a conspiratory air, as if there was something secretive about the words. She supposed he might think it impertinent or some such for a man so much older than her to comment on her 'loveliness'. He seemed that type.

Personally, Rose was mostly flattered. He was hardly like the old letches at the local pub who occasionally tried to cop a feel; he was far too mannered for that. While once upon a time she might have had a very different reaction all the same, she'd seen a lot weirder in recent years. If a tree and a Time Lord could flirt, and if someone like Jack Harkness could exist without the universe immediately exploding from sheer overload, then what was to say a man the Professor's age couldn't still cast an admiring eye wherever he liked. He was probably less than a tenth of the Doctor's age, after all, and she certainly didn't mind when he'doccasionally gone a little slack-jawed at the sight of her in some new outfit, or at the way she'd sometimes caught him off guard by beaming happily at him just because she could.

"People keep showing up, you see," the Professor was saying, apparently having moved onto one of his long explanations that Rose kept accidentally tuning out from. "Sometimes I really do wonder where they come from and how they get here, considering how little there is left of the universe outside this bunker. They can't all be hiding out there on the surface somewhere among the futurekind without being sniffed out, surely. Whereabouts precisely did you come from, Miss Tyler?"

"Oh, well, I'm not exactly par for the course," Rose fobbed him off.

"Oh?" he asked, raising his eyebrows at her. He was so earnestly interested that Rose hesitated to lie to him, or to say that she couldn't tell him, even though she knew she probably should. He'd been so kind to her, and she couldn't imagine him trying to steal the Cannon technology from her, even though she could tell that the concept would blow his mind in a way that none of these odd devices that Rose couldn't even begin to fathom the purpose of managed to faze him.

Perhaps that was what ultimately decided her; he was such a genius, so like the Doctor, that for once she wanted to prove that she had knowledge about something completely wonderful and unbelievable as well.

"I'm from another universe," Rose admitted. "A parallel one. I'm crossing universes looking for someone I lost. He's sorta one of a kind, though. Only one of him in allthe universes, or else things would probably go all wonky or explode or somethin'. I guess, thinkin' about it like that, it's not such a big surprise that I didn't find him straight away. He's a pretty small target, and I dunno how accurate this whole process is. It's really just a bit of an accident that I ended up here. Not that it hasn't been a nice little detour," Rose was quick to assure him.

The Professor sounded like he was barely listening to that last bit anyway, having been distracted by the more important part of her speech. "Parallel universes... there have always been theories, as far as I can tell from what books are left from earlier times, but to think it could be a reality..."

"I'm livin' proof and everythin'," Rose said proudly.

"You're extraordinary," the Professor claimed.

Rose blushed. "Er, well, not really. Not me. I'm just a girl."

"But that's what makes you so spectacular," he insisted.

It was exactly the sort of thing Rose remembered that the Doctor would unexpectedly come out with sometimes. Rose smiled and leaned forward, pressing her lips to the Professor's cheek in a quick kiss. "Thank you," she said sincerely.

"Oh, well," the Professor said, flustered. "Thank you, Miss Tyler. It's been such a very long time since anyone so young and pretty paid any attention to the mad old professor working away in the bowels of this place. It's nice have something to keep me going other than the hope that I might get this lot working some day."

Rose smiled encouragingly. "Of course you'll sort it out. You're brilliant."

She'd had no idea she had the power to make a man blush so deeply so easily. It was sort of intoxicating, and she could imagine wanting to stick around just to have someone pay her that sort of attention, and to help him in any way that she could considering how little she understood of what he was actually doing.

She had a job to do, though. The stars weren't going to stop themselves from going out, as far as Rose could tell. Also, Rose thought that she liked Chantho, with her all-too-clear crush, a little too much to make her go through watching on as the Professor looked at someone else the way she clearly wanted him to notice her once she got back from her nap, or hibernation, or whatever her species did at times like this. Rose knew what it was like to be overlooked for someone else, after all. It wasn't a hurt that she'd wish on anyone else if she could help it.

"I wish I could stay and help..." Rose began carefully.

"Oh, but you have to be moving on, don't you?" The Professor smiled, as if he didn't begrudge her how easily she could just pop out of the hard situation he and the others were stuck in. Perhaps he didn't. He seemed so selfless. "You have universes to see! If I had that sort of power, I'd never sit still, which is really saying something at my age, let me tell you." He may not have looked resentful, but there was a wistful air about him.

Rose understood at least part of the reason why the Doctor picked up strays. She'd seen it out there. How could she not want to share that?

"I'd take you with me if I could," Rose said truthfully. "But somehow I don't think you need my help to get out there and see the rest of space. You're almost there already, see. And I can't stay here either. Never know what it could do to things, havin' someone who's not supposed to be here around. I've learned that bit the hard way. You probably shouldn't mention who I am or how I got here to anyone just in case."

"Your secret is safe with me," the Professor vowed with a short bow. Rose got the impression that he was far too pleased that she'd entrusted it to him to even think of betraying that. "I promise also that I will try to have as much confidence in myself as you have in me, my dear. And I will hope that somehow your marvellous universe-travelling ability will allow our paths to cross again."

Rose reached out and patted his hand affectionately. "Tell you what. The Doctor might be able to give you a hand with all this! When I find him – that's who I'm lookin' for, by the way, the Doctor – I'll get him to bring us back here if I can. I dunno whether it's possible, since this might not be his universe. But I'll definitely try."

She caught a yearning in his eyes as she faded away at the press of a button. It made her even more intent on finding the Doctor, who she'd last seen disappearing before her eyes in just such a way.

The Dimension Cannon worked, clearly, well enough to take her right to the ends of some universe, regardless of whether or not it was the right one. It might need some fine tuning, but this was the closest she'd been to getting back to the Doctor since Canary Wharf. She wasn't going to let anything keep her away for long now.