He's talking to himself.
Well, he isn't. Except, well — he is, actually. He's been talking to the past and future versions of himself for quite a while now, and it's just as much of a headache as it's always been. Of all the past faces that could've turned up, it just had to be this one, the one he'd rather forget about.
That's not quite what he means, though.
"Do you remember this?" he asks the older him, after the queen and the girl whose name appears to be Clara come to collect them from the Tower. The two of them are bringing up the rear of the odd procession, while the younger him, the one whose jacket still smells of rust and ash and burning dalekanium, trails behind Clara and the queen.
"Bits and pieces." The older him won't meet his eyes while he answers. "It's coming back as it happens. You know how it is, being on the tail end of something like this."
"Well, I don't remember any of it. Being him, seeing this."
"And you won't, because I don't. Didn't." His older self wrinkles his nose in annoyance — an expression he recognizes on a face that he doesn't. "Blimey, I'd almost forgotten how quickly everything gets turned about when I meet myself."
"Have you noticed that there's—" He searches for a way to articulate what he's been noticing, ever since the younger him showed up. "There's something wrong with him."
The older Doctor does look at him then, with a dark expression that clearly says understatement, mate.
"Really, though." The Doctor points to the man in front of them, hoping that he's not being too conspicuous. "Just look. It's like—"
Like he's listening to something. Someone. Sometimes he mutters to himself, a little bit, like he's carrying on a conversation the rest of them aren't privy to.
As if to illustrate the Doctor's point, the younger him cocks his head to the side and nods, an answer to a question that no one else can hear.
A hot shiver runs through him, like fire in his veins, and for a moment the shuffle of their feet on the rushes sounds like music; like hushed voices, softly breathing out the notes of a song he's heard before. "I know we're not exactly the picture of sanity, but—"
Elizabeth — or the Zygon that looks like Elizabeth, he's really not sure where they stand on that front just now — cuts him off before he can finish the thought.
(Out of the corner of his eye, he sees a flash of something gold).
It's nothing new, seeing things out of the corner of his eye.
He'd barely been able to go five minutes without thinking that he'd seen Rose, right after Canary Wharf. Every sight and sound and smell was practically radioactive, toxic, for all that it was saturated with memory. Waking, sleeping, eating, breathing, living, all of it was wrapped up in her, and—
This body was born looking at Rose Tyler. It hadn't quite known what to do without her.
So of course he'd fancy that he actually saw her, sometimes. There'd be a spot of gold in his peripheral vision, or a bit of pink and yellow lost quickly in a crowd, and his hearts would seize up for just a moment — surging with hope and love and promise every time, even though it always turned bitter in the end.
He'd hoped that Martha would make it better. Instead, she'd made it worse, though it hadn't been her fault. It'd been his, really, and he ought to have told her — something. Something to make it better. To apologize. He can't think what, though.
Donna had made it, had made him better. Had made it all hurt a bit less. He'd still gotten that pins-and-needles feeling every now and then, though — the skin-prickling, hearts-stopping sensation of hope and panic and impending, inevitable disappointment all rolled into one.
Then Rose had come back. And then he'd let her go.
After that, he'd stopped seeing her in crowds and corners — though not, as it happened, in his dreams.
Those dreams add years to her age and lines to her face. She's older and wiser, with hair that's just a little darker and a smile that's just a little wider. Sometimes there is a ring on her left hand, and sometimes that hand is holding a smaller one. The hand of a child, with brown hair and brown eyes and a nose that he recognizes as the one in the mirror.
The Doctor hasn't tried to convince himself that he might be seeing her in a very long time. He doesn't want to — or doesn't want to want to. Rose belongs in his dreams, in the hazy-edged world where forever is a promise they can both keep.
But the longer this particular adventure drags on, the more on-edge he feels. The flashes of gold and the song in the air and the way his younger self's eyes stare at empty space, when he thinks no one's looking—
(Like someone walking on your grave. That's the expression, isn't it?)
He's talking to himself again. Younger him, that is.
They're standing around the Moment — he doesn't remember it being a big red button, but then again, he doesn't remember any of this — and his hearts are pounding double-time, a far-too-rapid quadruple beat inside his chest, because there might be a way out after all.
"She didn't just show me any old future! She showed me exactly the future I needed to see!" His younger self is ecstatic, pressing his hands to his head and smiling wide enough to crack his face in half. "Bad Wolf girl, I could kiss you!"
He'll realize, later, that while he'd been busy spluttering at his younger self, brain freezing and hearts stuttering, there'd been a brush of ghostly fingers across the back of his neck — that while one heart jumped and the other sank, not sure whether to be elated or scared out of his wits — he could hear the echo of a song.
"Sorry, did you just say Bad Wolf?"
No one answers him.
(No one has to).