The Doctor wasn't supposed to meet Clara again.

To be honest, he wasn't supposed to meet anyone again. For all his adventures in London, he'd figured it would be okay to stay in one place for a while. Besides, in this time zone, the Paternoster Gang were here too: Strax, Vastra and Jenny. With the city already under protection, he was no longer playing the part of Doctor. Now, if he so wanted, he could waltz right up to the ashes of Gallifrey and change his title to... Onlooker, or something like that. Something passive.

Of course, that was a joke. So was the notion that he was in any way enjoying it here. He wasn't happy. He wasn't healing, he wasn't resting. But at least he wasn't travelling. Never again. He'd done enough of that.

Gallifrey was gone. His family had been gone long before then, victims of a war that stretched timelines like rubber bands, over and over, until they snapped. And then, far more recently, he'd lost the Ponds to time yet again. Little Amelia, the girl who waited, and her Rory the Roman, who had waited longer than the Doctor had been alive (linearly, at least).

What was it about Victorian London that caught his attention? And why did the worst things always happen at Christmas?

He just hadn't expected Clara to come back. Even if Madame Vastra had reminded him that he was careless, left his ladder to the clouds exposed. He'd just gone for a walk, that was all. No Cybermen on his agenda tonight. Just a normal stroll. Wasn't every living bipedal entitled to a normal stroll where nothing happened? Even once?

It seemed he wasn't meant to walk, after all, but to run. Run far away and never be found and just keep running.

But Clara had come back! And that was a very bad thing. He wasn't supposed to interfere in her timeline. She didn't recognise him, at least not this face, and he needed to keep it that way. At all costs he had to keep it that way. He sure wasn't about to be in two non-linear relationships. One was already enough, and he was sure that time was nearing its end anyway. After that, the Professor River Song would leave him too, gone to meet her fate with a man who hadn't even met her yet. He even had the screwdriver ready to go, ready to scan her data, exactly as he'd remembered it, with the pull-cord and everything. He'd extended the scanner's battery life as much as he could, and prayed to the Triumvirate that it would last until she reached the Library.

He hadn't encountered Vashta Nerada since, not on that scale. He'd heard tales of scientists creating a virus that could kill the Dust in Sunbeams, even talk of a vaccine to protect living flesh against it. The Library incident had become well known with the centuries; thankfully he'd stayed out of the press for that one. Ever since Oswin did that miracle at the Dalek Asylum, the most comprehensive database on the Madman With No Name was redacted. He was free to keep being anonymous.

And now, before she could even give that gift to him, she was jumping into his timeline too early.

Oh, he knew all about her. Clara Oswin Oswald. Daughter of David and Eleanor Oswald, a family from the other side of the London tracks. But she'd managed to cross over, oh yes she did! Even did a bit of living and working in both worlds. Judging by her education, she was ambitious. And she was adaptable. Good. She'd have to be for whatever happened next.

He really should've picked another time zone. Perhaps next week, he would pull up stakes from the clouds, say farewell to his final companions and visit an island somewhere. Maybe ditch the box underwater and live with otters. That way he could drift with the currents, as he had always done, away from people. Otters could make good companions, couldn't they?

There was an aggressive knocking, and he sprung up from the console: BAM BAM BAM BAM BAMBAMBAMBAMBAMBABABABA -

He flung the door open - outside, not inside, exactly as Sexy had instructed him to but he rarely did, and his ploy worked: Strax was thrown to the ground. Well, not really ground, because it wasn't the ground, more like a superdense collection of vapour but that's -

"Yes, Strax, what is it!?" The potato butler got to his feet.

"Sir! We will begin the Sontaran Doctrine Seventeen Interrogation of the Oswald boy in fifteen minutes!"

"How many times do I have to tell you, Strax, it's a girl! You get them backwards." The potato sighed. In Sontar-ngok, the classical Sontaran language, the words for sigh and snarl were one and the same. The Doctor could hear the butler gliding between the two sounds.

"The Oswald giiiirrrl will undergo a Doctrine Seventeen Interrogation in..." He checked his pocket watch again, dropped it back in his coat. "...fourteen minutes, sir!"

"Good. Find out what she knows, use the worm again, and make her afraid of ever climbing ladders again. We can't have her finding me."

"I shall see to it! He will be branded with the iron of a ladder, and suggested, post-hypnosis, to be wary of all things climbable!" To the Doctor, that was good enough. He hadn't hear Clara talk of any brands on her body before, but such scars were shameful, learned from rather than shared or talked about. And he'd never seen her on a ladder before. Who knows?

("Doctor who knows?")

No. Stop that. Stop it right now.

But this whole quandary was making him feel something he hadn't felt in a long while, even since before he lost his human family.

The Doctor felt curiosity. He was already feeling himself beginning to burst with questions again...

...

...

...

...

The Doctor had met Clara before. Multiple times. Twice, even in this body!

When he'd worn the face of a weasel and played the recorder, in the 1960s, he had bumped into a local woman who yelled Cockney curses at him until he was out of earshot. She was short, round-faced and blended in perfectly - so perfectly he would not have thought twice about her.

When he was a walking catastrophe of insecurity and colourblindness, she had been a passenger on board a spaceship. Again, it was not necessary to notice her, but the Doctor never forgets a face.

And when he was still travelling with... them... he had heard her voice, guiding them through a world meant to hold the invalids and the insane of the Dalek race. Thankfully he did not encounter any Degradations, he did encounter something different: a girl named Oswin, who had been converted into a full Dalek for her brilliant mind, but dissociated and living a delusion that she was living in the wreckage of her ship. She had given the gift of erasing him from Dalek databases from her point in time onward. Perhaps forever. They didn't even remember the Time War, he realised. It hadn't happened for them, either not yet, or not at all. Most Daleks still around didn't even know of Gallifrey. They were, in effect, no longer the same race. Still Daleks, and now he was trapped in a memory.

But it was her voice. And he'd figured out the truth: Oswin had not been her real name. It was a misremembrance of her surname, Oswald, as her identity was corrupted and partially overwritten.

But this... Clara. He'd been keeping tabs. Not too closely, but now he couldn't afford to look away.

He wanted to know what all she'd seen, before they used the worm on her repeatedly... and Strax had forgotten his gloves and dropped it.

He came down from the clouds to observe the hypnosis of Clara Oswald.