Disclaimer: They would be, if they were mine instead of the BBC's.

Soulmate

In life you will meet one person who is unlike any other.

You could talk to this person for hours and never get bored, you could tell them things and they won't judge you.

This person is your soulmate…

Your best friend….

Do NOT ever let them go.

Donna looked down, a faint smile gracing her lips as she regarded the Doctor, his head in her lap, slumbering peacefully. The movie they had been watching had long since ended, but she was reluctant to disturb him; he didn't really get that much sleep, because he didn't need it, he claimed, and on a physiological level maybe he was right.

But haunted as he still was sometimes by the nightmares of long-ago as well as the not-so-distant past, sleep was a way to escape, and so she let him journey on down the path of temporary respite, her finger lightly smoothing his sideburn as his gentle breathing periodically tickled the baby-fine hair on her bare thigh.

There was such a comforting familiarity in where she was right at that moment, for it was a position they so typically found themselves in, after another day in their anything-but-typical life.

Which planet they would visit, whether they travelled forward or backward in time, who they met, what disaster they averted, which right they wronged, who they saved….the tangents, the variables, the possibilities were too dizzying when she tried to consider it in much depth, and it was sometimes quite disconcerting to think that whenever she got up in the morning, she couldn't be sure if the day was going to end with her getting sand in her bathers and a bad case of sunburn or barely escaping with her life.

She did know, though, that once they were back in the TARDIS, that there would always be some kind of this, the quiet, completely content togetherness that only happens between two people who are each others' very best friend, who are so comfortable and secure in themselves and the nature of their relationship that there is room for the biggest, most all-encompassing of love. Accepting, challenging, encouraging, comforting love.

Love that healed.

Love that saved.

She didn't pretend to completely understand him – how could she? It wasn't even possible for her to fully understand another human being, let alone a near-millennium-old alien, but she understood him enough to know the truly important things about him – his love, his loyalty, his passion. That she was the focus of so much of it now as his companion – in every sense of the word – well, that was just about too much for her to comprehend as well. But she didn't need to know, or understand, everything about him to know that he was her soulmate, the person who got her more than anyone else ever had, or would.

Oh the irony that that person is the most different to me that someone could possibly be. That a man from a complete alien world, which has long since gone, is whom I feel most at home with.

When it came to knowing in the Biblical sense, Donna was no babe in the woods. There had been flashes of frenzied, heated lust that at the time she had thought was passion, and she remembered thinking that maybe this was part of what she needed, that the rest, the foundation on which she could hang all that sexual energy on and build something lasting, would come in time. But of course she had been mistaken and it never did; to the contrary, it only fed her lack of confidence and the low self-esteem that had festered (and been fostered) since she was a child.

Meeting the Doctor had changed everything, turned her world, her thinking upside down, for here was someone who made no demands, expected no 'favours', who for God only knows what reason, had decided that he wanted to share the wonders of the universes with her. Not only that, he had fixed upon the notion right from the very start that she was magnificent. And brilliant. It had taken so long for her to believe him. But when she had dared to start, oh, she had never imagined life could be like this.

They'd started off as mates purely for reasons of emotional self-preservation; he'd told her as much, and she pretty much knew it was the same for her, though she didn't admit it at the time.

At what point she'd changed her mind, from thinking of 'mating' with him as something slightly horrifying to having it stir the deepest of longings within her, she couldn't really say. It was more like a slow, steady process with barely-discernable steps yet whose outcome was all but inevitable. As close as you could get to what some would call destiny.

Something she never used to believe in.

She smiled ruefully.

I do now.

Intimacy with him was nothing short of a revelation. A complete re-ordering, restoring, revitalising of her thinking. As her mind drifted back to the sparkling turquoise river and gently waving, feather-soft tangerine grasses of the planet where they had just spent the entire day very pleasurably, without – miracle of miracles - any untoward incidents whatsoever, it occurred to her that making love, when it was with your best friend, was rather like drifting lazily down a wide, meandering river – gentle, unhurried, languid, and beautifully sensuous. As opposed to the emotional bruising and bad taste (metaphorical or otherwise) left in her mouth by previous lovers that was more akin to the rough and tumble of being dumped mercilessly by the surf.

That wasn't even the real beauty of intimacy with her closest friend, though. The truly exquisite, precious thing was knowing that even when she got old, and her looks faded, and whether he regenerated into a completely new face or not, through all of that, their friendship, stronger than ever, would remain the bedrock of their union, and that the intimacy of truly being in synchrony with him would be a more than adequate replacement for decline in physicality.

He murmured softly in his sleep then, snuffling a little as he turned to lie on his back, a hand reaching up instinctively for hers. As she grasped it and squeezed gently, he did not wake but sighed happily, a soft smile crinkling the corners of his closed eyes, his long lashes fluttering delicately.

She swore to herself that she had never seen anything so beautiful.