Back at the hospital, the Doctor leans back in at the quarantine room. First things first, he looks at Lizzie, "How's the patient?"
She shrugs, "No change. And I'm not sure I can change him." The Doctor nods. He was expecting that.
Had Adam, while he was out meeting the strange Mrs Lees, decided to get up, wipe the sleep from his eyes and do a little dance, that would have been something off his plate. That would have been very nice. That's why he's not surprised. Nothing is ever that easy. He's got a big, tangled, knotty, complicated problem to deal with, and it's just too much to ask for that one of the big, tangled, knotty, complicated strands within it would have just vanished.
"Sorry," he says to Lizzie. "I promise you, you are one of the single most useful creatures ever to grace this planet. I've just happened to bring you somewhere where you can't be of use. I didn't mean to make you feel bad."
"I don't-"
"Oh good," he looks away, opening his mouth to call for Jessica.
Lizzie cuts him off, "-But could we speak? Just you and I?" He looks back. This time, he looks properly. This time, he really sees her.
In her own time, Lizzie would have been considered a fully grown woman. Her community, while it never fully accepted her, had respected her until recently. She'd done rather well for herself, while her mother had lived. She'd been doing well for herself alone until they decided to burn her. In her own time, Lizzie's talents were appreciated. More importantly, they were limited. How could she ever access her knowledge of 21st century medical equipment without access to 21st century medical equipment? In her own time, Lizzie knew what she was and she knew where the boundaries were. He took that away from her, and left her in this room to play the nurse.
"Of course," the Doctor tells her gently. He gives her his hand and the two of them step into the hall. He's got his mildest face on. It's his 'listening' face. It's his 'No, River, I'm not messing about anymore, I'm paying attention to you' face. It's his 'Please don't hit me again' face, in related circumstances. He's here. She is all he cares about, right in this especial moment. "What was it you wanted to talk about?"
"Nihilium."
"Oh." Not her temporal and cultural displacement then. He takes his listening face off and puts on his 'joy of science' face.
Yes, there's a face for the joy of science. When you have reached a millennium and a half in age, you will have a face for everything too. "Well, fire away, then, Liz, I could talk about this for hours if you want." Lizzie flounders, a little stuck. "Start at the very beginning," he smiles.
She mumbles in reply, "It's a very good place to start." Mumbles it tunefully, too, catching up on that.
"Tell me what you know."
"It's an element," she begins. "The finest and lightest element there is, which is why it took humanity so long to discover it." These are all facts that the Doctor already knows. He nods along, confirming for her that she's on the right tracks. "It composes those parts of a person that we had always thought of as the soul – the love, the memory, the self, the personality. The immortality and individuality of any creature is contained within its nihilium stores."
"All of this is absolutely true."
"I've been speaking with both Jessica and Clara, and they've both had experience with nihilium, with the damage and extraction and the content of it."
"This too is true," he nods, but raises one finger in warning, "though something of a sore subject with them. Jessica especially. She was a tiny bit dead for a minute due to depleted nihilium stocks."
But Lizzie's not finished. That wasn't the point she wanted to make. She's coming to that now and she's not going to stop until she's told him, "There's a thriving black market trade in extracted souls and yours is on the most wish-lists, demanding the highest prices."
After that, there's a little bit of quiet. He wasn't quite expecting her to come off with that. Not that he's shocked. When one is terribly clever and terribly old and has been absolutely everywhere (except for what's beyond a small meteor belt in the Destry nebula. He doesn't know why. It just looks dark and uninviting over there and he's never chanced it), it seems only reasonable that one's immortal self should be in great demand. It's just that he had expected her to be a little more, well… tactful about it.
"Lizzie, this might not seem like the time, but there's a thing called foreknowledge, and you're really not allowed to give it out."
She shakes her head, "There is nothing 'fore' about this. It's now. These records, the ones in my head, the ones I can draw on… Whatever they are, they're telling me this appertains to you here and now."
Oh. Jolly good. There's something else to add to his plate. Balancing on the edge, like a slice of toast on the edge of a motorway services fry-up, the kind you can't balance and the beans are always sliding everywhere, and the strangest parts of you end up with tomato sauce on them. In the interests of preventing a nervous breakdown, really rather unadvisable at his age, the Doctor forces himself not to think of this as another part of the mystery. Rather, this is obviously a tool for cracking mysteries open.
In a breathy, small sort of way, he begins to laugh. Lizzie's eyes widen. Cautiously, "Doctor?"
"Oh, don't worry. Not having a nervous breakdown. Actively taking steps to prevent that. No, I… Promise you won't laugh at me?"
"Why should I, when you clearly find yourself so amusing?"
She's wonderful, isn't she? He knew he was going the right thing, when he went to find her. She's wry and hard and knowing. She's delightful and he laughs a little louder. "I thought you wanted to talk because you're alone and in a strange world and full of new powers. I thought you needed me. And here you are warning me of the looming danger to my higher self."
She raises one eyebrow. She understands what he's saying, of course. But she still doesn't find it all that funny. "This seems a little more important, don't you think?"
"I wouldn't blame you."
"When the time comes that I need to talk about that-"
"I'll be here," he says, and means it. Meaning it helps to straighten his face. He gets up from leaning on his knees, clears his throat. "For now, however, you couldn't have a little poke around that big supercomputer brain of yours for me, and have a look for a name?" She nods and he gives it to her. Missus Lees, he says, but if the married name doesn't work, how many Toffees can there be in history?
Lizzie pulls a hank of hair down over her shoulder, running it over and over through her hands. A little habit. He likes it. So much more fun than asking a normal computer. Much more friendly than a loading bar, don't you think? She really is very ginger, you know. Proper carroty orange bright celtic ginger. He's almost disappointed when he sees her mouth open and knows he's about to get an answer. "There's nothing." Well, now he really is disappointed. But she hasn't let go of her hair yet, and her brow is still furrowed. "Or there could be, but it's being buried."
"What do you mean 'buried'?"
"Mrs Toffee Lees," she echoes to him. "It's a pun. There's an Earth myth, about a man named Faustus? He sells his soul to the devil. The demon who manages the transaction and oversees Faustus' time on Earth is named Mephistopheles. Missustoffeelees. The joke disguises her."
The Doctor is frozen. He knew that. He knew the story. He knew the name of the demon. To put it simply, he got the joke. And yet, until Lizzie said it just now, it hadn't occurred to him. The sensation is strange, disjointed. It makes him a touch uncomfortable and that is what gets to him most, because after all these years there is very little that can make the Doctor's skin creep.
Lizzie looks into his glassy stare and he snaps to attention. "If you think of anything-" he begins.
"It used you," she breathes. "I see it." She picks up one of his hands, studying an aged liver spot he hasn't been able to get rid of. When she touches his forehead, there's a slough of dead skin to brush away; the wrinkles Mrs Lees gave him. "The demon, Doctor, it… it got to you."
"That's why I need you to keep trying for me. Anything you've got, anything you can dredge up. The silliest thing could be vital, so tell me everything you come to learn."
"But how do you intend to fight something that can change your actual self? If it aged you, couldn't it kill you? Couldn't it will you out of existence?"
He turns his hand over and holds hers tightly, "That's why I need to know all I can, and really, Lizzie, what on Earth is going on in there?"
Not what he meant to say. He meant to tell her he appreciates that this must be difficult, that he's grateful, and that there's no pressure.
But just through the soundproof glass he can see Jessica grinning, bobbing her head side to side as she chants something. Clara, meanwhile, looks straight-backed and utterly indignant. The Doctor watches the red blush rise out of her collar. It's approaching her ears, shooting right for the hairline, when he pushes open the door to interrupt.
"…sitting up in tree, k-i-s-s-i-n-g, first am coming love, then is being-"
"Jessica Apple!" he snaps, shocked and disappointed with her, "Is that what they're teaching you at university these days? What on Earth do you think you're doing?"
"Claraperson am having much big fancy-feelings for him."
The Doctor straightens his lapels and tries not to let himself puff up too much. "Yes, well, that's hardly a cause for laughter, now, is it? After all, who could blame her? And shame on you for teasing the poor girl over what she can't have."
"Not him-"
"Oh."
"With SleepyAdam. Was saying is much handsome."
The red has reached Clara's temples, and is being swiftly followed by the next shade down, "I never did!"
"Yes-did. Yes-did and says was being much 'cute in sleeps'." Jessica loses herself in another bout of giggling, rolls sideways, almost off her chair.
The Doctor bites in his lip. Mumbles through it, definitely not laughing, not even starting to laugh, "Clara, that's a coma patient at best, what are you thi-" The word does not get to be completed. But he doesn't laugh. He just has to close his mouth very hard to keep it in. He tries to beckon Jessica, but her eyes are shut. Eventually he has to go and get her, picking her up by the shoulder and pushing her out of the room ahead of him.
The last thing he hears, before the soundproof door closes, is Lizzie telling Clara, "If I can get him awake, I'll make sure you're the first face he sees."
The Doctor and Jessica lose the first minute of their private conference hissing and breathless, laughing themselves into silence, until she tries to lean on him and the full weight of her comes down on his toe. "No, no, this'll never do," he decides at that moment. "We're being awfully mean and anyway, ouch."
"Much sorry."
"Don't be. But make it up to me."
All of a sudden, she is straight and serious as a soldier. She's earnest, devoted, snaps out, "Right-yes, Doctor."
"Do you remember you used to do quite a bit of sneaking and spying?"
Jessica looks at her shoes. In her tiniest voice, "For bad-Owner and bad-Silents. Yes, Doctor."
He tips up her chin, "For me and River too. And much appreciated you were. But I need you to do it again."
"Her am guards Clara, though."
"Oh, I think I can manage a shift with her. I'll think very sad thoughts the whole time and hopefully manage not to offend her." Jessica begins to protest; that wasn't what she meant. She doesn't, please, doubt that he can protect Clara much-well, but just feels she's slightly more qualified for bodyguard duties. She has prior experience in that too. The Doctor blithely ignores every word, takes her under his arm and starts her toward the lift. When she is quite finished giving her argument, he tells her precisely what he needs her to do.
[A/N – Like Lizzie says, Clara and Jessica have both run afoul of nihilium-based nastiness before, in the stories 'Memento Vivere' and 'No Place for Scholars' respectively. Or you can just take Lizzie's word for it. She knows a lot of stuff, after all.]