Clara is holding his hand. The Doctor's not sure she's even aware of it, but her fingers are knit through his. They only claw tighter when he sets his other hand over the top. He doesn't mind. Of course he doesn't. At least they've got plenty of time for it. They're still headed back to 2086, but the Tardis knows she has to loop around 800 B.C. a few times, until they're good and ready. The Doctor quite likes the warmth of her little hand, and its strength, and holding it.

But Clara doesn't feel like she can let go. That's what he doesn't like. He had to calibrate their destination and realign the rotor and take off, all one-handed.

And so, while the poor Tardis idles, spinning a few thousand years around the block, he takes her wordlessly to the nearest kitchen and sits her down while he makes tea.

"This looks an awful lot like the Maitlands' kitchen…" Clara murmurs.

"Really? Hadn't noticed. Don't draw spurious conclusions; it's not like I put it in so you could feel at home and maybe make me a soufflé sometime, seeing everybody else gets soufflés." Her smile is dim and forgetful. It is, at least, a smile. That's enough for him to continue. "Clara, I do need to know what's going on. After all, I've only managed to delay our meeting that gentleman again." She doesn't like that. Flinches when he says it. Finally lets go of his hand so that she can hug herself.

"I didn't mean to cut you out," she says, "or worry anybody. I just didn't know what to do."

"Start," he says, "at the very beginning. I'm reliably informed that it's a very good place to start."

Clara draws in a deep breath. He brings her tea and she sips at it. "It began," she begins, "two nights before the night we just left behind. He says his name is Louis, but I'm not sure that's true."

Quietly, evenly, she tells him the story. She had gone to pick up Angie and Artie from school. A little early, standing at the gates. Nodding along to the sound of the music in her headphones. She didn't even hear him slide up to her, and gasped when she felt the lithe, polite hand tapping her shoulder. Clara describes her initial reaction to the awful man in terms the Doctor finds very comforting; she felt the same way he did. Here before her was the idea of a gentleman. A natty dresser, a surface charmer, impeccable manners. But that was all. The rest was missing.

What rest? They would find that very hard to relate to you.

The Doctor does have one metaphor you might understand. He would ask if you remember the man in the pit, in the collapsed subway tunnel. And if you remember that, perhaps you remember Elizabeth King. A middle ages witch was able to diagnose the man's condition where all future technology had failed.

She said that he had been stripped of all self, of all humanity, except that one little spark in him refused to go out. Hence he blinked. Hence his heart marches on beat by beat.

The Doctor would ask you if you could imagine that. And if you could, perhaps you could imagine just the opposite. Because what met them on a cold suburban street last night, what crept up to Clara at the school gates, is a creature just as devoid, just as empty of life and joy and human kindness.

But there is no spark that keeps this thing alive. Instead, at the heart of it, is nothing more than a glowing black coal. The exact nature of it is still a mystery. Whether the mock gentleman is driven on by avarice or ambition or revenge or which of the darker forces, they still don't know. The Doctor fears most gravely, it won't stay that way for long.

It's a lengthy process, hollowing out a human being so completely. It takes even longer for the effects to show in the bearing, on the face. And both the Doctor and Clara saw Louis' nothingness at first glance. What does that tell you, then, about the depth of his evil?

That first day, at the school, he said nothing of any real note. More than once, Clara asked him if he was waiting for a child. He dodged that question. Gave her the distinct feeling he was waiting solely for her, and that speaking with her was the only reason for his present. They talked about the music she was listening to and the shoes she was wearing. He tried, more than once, to make her talk about the kids.

"He would smile," she says, from behind a nasty memory. "Right when I was getting most suspicious, right when I was about to start getting angry, those moments, he would smile. I think he's some sort of mind reader."

"No."

"You weren't there, Doctor-"

"If he could read minds he would have known I was only pretending I knew who he was." More likely, he's a cold reader. One who is highly practiced in reading body language and expressions and all the minute signals a person gives off. One who has studied human behaviour; perhaps in order to mimic it better. "Go on. What happened then?"

"Well, nothing, right away. The bell rang and the kids came running out. I looked round for them and when I turned back… he'd vanished."

It was the next day, she explains, which really worried her. The next day, he met her as she left the house on that same run.

"I forgot my phone," she said, and wanted to run back and fetch it. Run back to the house and call the police and hide. But he spoke to her. She'd make herself late for the children. What would she need her phone for anyway? She'd last half an hour without it. And Clara found herself thinking that yes, this was true, she'd be fine, why would she need it? He went on talking. They walked peacefully, most amiably, together to the school gates. Maybe, she started to think, she had misjudged him. Maybe he was just odd. Making conversation. He was wry and witty and Clara found herself laughing even.

Then, right before the bell rang, "Miss Oswald?"

"Yes?"

"I'm going to need you to deliver me the Doctor. Tomorrow night. That little park we passed a few corners back. Eight p.m."

Clara says she panicked. The Doctor smiles at her when she's not looking, beaming with benevolence and pride. It's not true. She didn't panic. She was scared, yes, to the very heart of her, but she did not panic. She was brave and strong enough to say, "I don't know where he is."

"Find him," Louis insisted.

"It's not like I can just whistle and he'll come to me."

"You would have had to whistle very loudly," the Doctor agrees, "and for a very long time. And possibly whilst travelling faster than the speed of light."

"Well, that's sort of what I was trying to tell him, I think! But he wouldn't listen. I would deliver you, he said. I'd be right there and I'd be bringing you with me and… Doctor, he kept saying all that. But he wasn't looking at me. The whole time, he wouldn't take his eyes off the school. I didn't know what to do. I was just so frightened and I didn't know what to do. There was you, but then there were the kids to consider as well. That's why I was teaching them your number. So you could come and help them if something happened to me."

His hearts swell, breaking for her. Not so that he could come and help her. So that he could come and protect her charges. Just the thought, just reliving it, there are tears in Clara's eyes. "Oi," he says, "Oi, c'mere," and pulls her into a new and tighter hug. "Silly thing, listen to me. Whoever, whatever and whatever-desiring sort of a thing that this Louis is, he is currently eighty-three years and thousands of miles away from Angie and Artie. And you, for your part, are with me, which is just as good. I won't let anything happen to you, Clara. You don't have to try and save everyone anymore, alright?"

After that, he waits. In a moment, what will happen is that Clara will crush away all of this nastiness. She'll put it aside to be dealt with later in small, manageable chunks of trauma. It will go to bed, and she'll spring back, chirpy and bright and ready for the fray. She'll say something breezy. Be dead feisty, and inspiring. The Doctor will want to leap into action.

He waits one whole biscuit for this revelation, and most of a cup of tea. Nothing happens.

So he slides his elbow in beneath her arm, just grazing her ribs. "Do you want to know what's in 2086?"

"I'm really hoping you're not going to put on your big stupid grin and say 'naff all', because I don't want to have annoyed that man."

"It's not 'naff all'. Far from it." Something starts to edge back in. Not joy or excitement precisely, but something. A glow, if not a flame. "Currently stored away for your intrigue and pleasure in the year 2086, are a vast alien intelligence which believes it's a witch from 15-something-or-other-"

"Another vast alien intelligence? Better be a nice one this time…"

"-A young-old-ageless man who's had his soul all but removed-"

"Again? This 'soul' business is turning into a theme."

"-And a one-time assassin who's just finished uni."

"Oh, how is Jessica these days?"

The Doctor laughs. With his arm still hanging around her shoulders it's no chore to pull her tight against him just once more. "While I'm tremendously sorry it's put you in harm's way, you were clearly born to live the companioning life."