Through Jessica's eyes, Soul the Visitor reads Rule Number Five to itself and gives a long low whistle. "Kill them dead in both their hearts," it says aloud, sounding stunned, scandalized. "Scary biscuits for you and the lady wife, Doctor. How do you stand it, by the way? It's like having a club on a Saturday night going in your chest."

"How do you stand being so ill-equipped, and slow, and lopsided?" I retort, instinctively. Then see it smile and realize I made a bit of an error there.

"You're under duress, Doctor. We won't count that as a quid pro quo question." In light of what we just discussed, I am about to ask it what exactly it actually is. It's a fundamental question in Tardis-board race relations, and I haven't gotten around to it yet. I open my mouth, and I draw in breath, and it lifts up Jessica's big bright eyes and stops me like they were a Gorgon's eyes. "Ask her how many she's murdered."

Oh, dozens, I should imagine. If I add up the Ghost stories of my childhood, there's fifteen or so there, and probably more. Oh, just dozens, surely. No point in fixing a number on it. No. That's not an irresistible question at all. No. Just damn close to it.

"What are you, really?"

It nods, benevolent, conceding its respect for my self-control. "What the name says; I'm a soul without a body of my own. I'm all the real bits of a person, without the real bits. Think of a person as like a really mediocre dancer, but wearing a glorious spangly dress with all feathers and trimming and such."

"You are a disembodied piece of cheap tack dressed up as more than it really is and you can't dance. Right, got it."

"That's not how it is at all, but if it helps you think of it that way, you knock yourself out." That's odd. That's my thing, making false comparisons for the benefit of beings of lower intelligence. Where has it heard that and how does it know that and why did it make a point of doing it for me? None of those are questions I can afford to ask, though. And anyway, it's this Soul's turn. "And for your information, I'm a wonderful dancer. Speaking of, what's River's favourite song?"

"Otis Redding, These Arms of Mine."

It makes the buzzer noise from that damned game show Amy watches, then singsongs, "Wrong. But it's good to know what you think."

It's lying on the couch again, this time on Jessica's belly, kicking her booted feet up behind in slow, gentle arcs. Enjoying, maybe, the sensation of being able to do that. I shouldn't be thinking analytically about it, when analytical thinking can so often lead to sympathy, but what's it like to live without form? What exactly is the payoff to being a parasite?

I didn't say that out loud, so it doesn't technically class as a question. I'll bring that up if Soul does. Because somehow, she knows what I'm thinking, and she answers it anyway. "Nothing. Absolutely bloody nothing scratch zip zero none niet nada nought. Except you get to be a tiny bit psychic when people are thinking about you. And I prefer the term 'vicarious-experience life form' to 'parasite', please."

Interesting. I make a mental note of that statement, to use later on when it's leaving forever ne'er to return, in fear of its very existence even as a vicarious-experience life form. I say nothing now, of course, because it doesn't do to overshoot one's false start, or however the humans split up the phrasing of that. Also because Visitor Soul is writing on the lines below Jessica's list of life lessons.

"You're writing."

The careful wording makes it laugh. "Yep. I got it from River, see, how you ended up locked in here in the first place. And it's not fair, that she wanted the two of you talking and I've, as you so nicely put it, Doctor, gatecrashed. So I thought I'd give you a hand and dredge up the rest while we're here. Get you both started."

It is quite without thinking that I go to the back of the couch and lean over, reading over her shoulder. Because despite this unwelcome presence, I still feel very much as though I am with Jessica. Which is another worrying factor because all Soul would have to do to go unnoticed is play the part of a pokerfaced mute. Now, given, I could clap by its ear and see if it jumped, but I can't do that all the time. Jessica would eventually come to distrust me again, if I were to start all that.

Soul goes back up the list and adds numbers to each line.

'6 –dot-' I read in its much neater and more even handwriting. Then it says aloud, "'To kill them, Owner will send it to Outside. It must try to forget everything that it sees there. The more it remembers, the more there is for the Twohearts to sense.' My days, you Twohearts are a talented people." She looks over her shoulder, then turns onto her side, and smiles like a little girl discussing television characters, "Hey, who was your favourite Time Lord, back when there were more of you?"

I pity Soul, you know. If I was to be a disembodied mind floating about the universe tormenting people, I would like, at least, to be secure in myself, and undamaged. This sort of bipolar personality it has must be a real curse when you've got no human contact. Nobody to take it out on but yourself. Trying to make friends one minute and wound the next, it must be hell.

"It's my question, remember?"

"Can't blame a poor soul for trying."

As I go back to the chair, it sits up to watch me. And I sit down first, because I know sitting down at whatever answer it gives me would be cliché and unnecessary and it is always best, after all, to be prepared. I will need to be prepared, you know. I've been walking around thinking about this for a while and I think I will need to be prepared.

"A question for Jessica," I say. Which is a stupid thing to do, because this Soul could be lying. And it says it was called, and I haven't asked who by, and there must be a reason why it's doing this, and I haven't asked what it is. Still, I put to it, "A question for Jessica Apple. How many Time Lords has she killed?"

Soul smiles wanly, and it annoys me to see that it suits Jessica's face. There's something old and exhausted about it. "None," it says. Then, before I can rage at it for the liar it is, "When was before-designated, though, when him am to have been calling her Little Ghost, Keepernumber was being eighty-one."

That is the point at which I would have needed to sit down. It is the point, currently, at which I fall back in the chair, and very briefly shut my eyes and wish that there was nothing here anymore. I stole a scone, you know. I insulted Pond over a scone and it's all just spiralled out of control. If Scone wasn't all rotted away I would eat him without mercy or remorse just now, and end all this forever. But it would seem, sometimes, that the road just doesn't fork, but goes on straight and inevitable.

Where have I heard that before?

"You know," it says softly, "it's alright that you had to ask that. It's just… closure, sort of. I could write you a list, if it helps."

"No. No, that wouldn't help. And anyway, it sounds like it might take a while and frankly, Soul, I'm getting a bit tired of your company and a bit claustrophobic in this room. Might be about time to start finishing up, I think…"