Author's Notes: The Doctor's solo travels between 'The Waters of Mars' and 'The End of Time' go on for far longer here than we're led to believe in canon. I leave it up to you whether it's a case of the fic being an AU or the Doctor just hiding the truth of things (because that's unprecedented, right?).

I had a conversation with Jack Harkness today. I couldn't remember the last time we walked away from such a thing without at least one of us having to use slightly off-key jokes and casual expressions to cover up the feeling that we were breaking apart.

This was no exception.

"You can't keep this up," he advised me as he slid sinuously onto the stool next to mine and ordered me a double shot of some foul-sounding brand of whiskey that I couldn't imagine this particular regeneration of mine enjoying.

"I'd prefer a daiquiri," I said without looking up from where I was tracing the grain of the wood on the bar; it was an easier thing to focus on than anything else on which my mind threatened to dwell.

"Sorry, Doc," said Jack. "We're more than past the time for the light stuff, by the look of you."

I couldn't really protest that. How bad didI look, anyway? The fact that it was the first time in years that Jack hadn't greeted me with 'hey handsome' was certainly telling.

"How long's it been since you've travelled with anyone?" he asked, sounding concerned.

I shrugged. I downed the shot with an exaggerated grimace and didn't ask for another, even though my overly swift metabolism meant I needed to soak in a good deal more alcohol to get as properly sloshed as I would really like.

Jack snickered, though whether at my expression or just at me in general I couldn't be certain. "What, you're telling me the Time Lord's lost track of time?" he asked. "Even I'm managing all right, and I don't have the skills you're always bragging on about. Plus, it's probably been longer for me than for you."

"Not this time," I admitted. "The last time I travelled with someone was you. That forest on Ytapia, remember? And unless I'm wrong – and I'm finally old enough to be willing to admit that that actually does happen on occasion, I'll have you know – I believe you're at the stage that you've run into a younger me several times since then."

Jack shook his head, looking vaguely disgusted. "But that was years ago. Decades."

I shrugged again. "So what if it was? It's hardly the longest we've gone without seeing each other. And we're both old enough that a decade isn't really a long time at all."

Jack eyed me sadly. "Aren't you old enough to stop lying about that sort of thing as well?"

If I were a different man, or maybe just a different regeneration, I'd have probably told him to go to hell. Jack had given up the right to comment on the more private aspects of my life a long time ago. But picking a fight was hardly what I really wanted to do with Jack. It did neither of us any good for me to either hide in my growing bitterness or to take that frustration out on him, even if he was a far bigger part of the problem than any of the many transitory companions who'd made me decide to stop showing the universe to people who I knewwere only ever going to amount to joyride passengers.

I gave my second heart to two mischievous humans long ago. I could never take it back. It was indescribably painful, and I felt hollow, but I could still manage to live without that second heart, knowing that somewhere, even split as it was now across multiple universes, it would always be safe in their hands. I couldn't live without the only one I had left, though. I couldn't give that one away, knowing I'd be left gasping and too crippled to carry on.

Jack had never understood this. Jack gave his own single heart again and again and somehow ultimately kept on walking, even if occasionally he briefly stumbled. I supposed that it helped that even literally plucking the still-beating organ right out of his chest wouldn't be enough to kill him for a minute or so at most. I found that I didn't envy him that at all.

I wasn't capable of just moving on. Even if Rose had, albeit with another version of me. Even if Jack had as well, probably at least in part because Rose had been the glue that held us together. They were human... adaptable. Time Lords had been accused of lots of things over the years, but never that. Not even me, renegade though I might have been.

I didn't doubt that they both still loved me. I could see it in Jack's eyes, and I was sure I would in Rose's as well if I could ever see her again. That had never been the problem. It was whether that was enough that was in question.

Jack closed the gap between us and placed a brief kiss on my lips. I'd have clung to him and deepened it – my body was crying for me to take advantage of this reprieve against my loneliness – if I hadn't recognised that it was just a momentary balm, with an overtone of 'goodbye' shadowing the touch.

There was the answer to that question. It wasn't enough, at least for Jack. The realisation felt like a physical twinge.

"Don't go and let a whole century go by without finding me again," Jack ordered.

I saluted mockingly at him, but we both knew that I'd probably honour his request anyway. I owed him a simple request like that. He could break my hearts as many times as possible – shatter them completely, even – and I'd still owe him.

With a final smile, Jack turned to go. I'd let him walk away without protest many times before, and it had always been a mistake. This once, I called out to stop him before he got far enough for the din of the pub to drown out my voice.

I told myself that it wasn't a risk to my heart when he already owned at least half of it. Even if it was, just the slightest potential that something good might come of it would be enough, because it was him.

"What if I don't want any time at all to go by?" I asked. "You could come with me. Now. Not just for a single trip here or there. For as long as you like."

It was hardly the first time I'd made a similar offer, and it was hardly the first time he'd turned me down either; I could tell by his wry smile that that was precisely what he was planning to do.

He surprised me, though, at least in part. "I've got places to be... people who need me. But you should ask me again next time I see you," he said. It was clear that there was some part – perhaps even the main part – of Jack that didn't really wantto leave me this time. If there was one thing I understood, though, it was putting duty above everything else.

So when Jack moved to go a second time, and this time I let him.

It was a peculiar sort of comfort that Jack had offered me. In a way, the gift of some manner of promise for the future stung almost more than an outright refusal to ever consider what I was asking of him would have, because the anticipation made me feel again. But hope, even if it hurt, was something that I'd never quite been able to grow beyond needing, and never really wanted to (for what kind of man would I be then?).

I'd long since figured out that I couldn't get over those two people that I loved, even if I never admitted that word aloud to either of them. But being alone was killing me as surely (albeit far more slowly and insidiously) as taking a chance and being actively trampled on afresh by the universe for daring to believe I could be happy.

It wouldn't be the same if it was just Jack and I, with no Rose to smooth over all the little cuts we'd undoubtedly inflict as we grated on each other. And I doubted we would ever reach the kind of near perfection we'd experienced back then. But I still knew one thing.

It still had to be better.

~FIN~