It's completely an accident, the last time it happens.

(He's nearly a thousand years old, after all; Time Lord or not, a bloke's bound to forget a few paradoxes, isn't he?)

"Are you sure this is the right place?" Amy asks, frowning. She glances about the wood, sunlight streaming through the white-and-silver leaves, painting her face in dappled shadows. "This doesn't look like Neptune, the year 398099. Or not how I expected it to look, anyway."

"It doesn't, does it?" the Doctor replies, kicking at the dry leaves scattered on the ground. "That's because it isn't."

"Neptune, or the year 398099?"

"Either," the Doctor says cheerfully.

He pauses for a moment, having a think. He licks his finger and holds it up to the wind. "Actually, no, wrong again, it is the year 398099, it's just entirely the wrong planet in entirely the wrong quadrant."

"Oh, is that all?" Amy asks, her voice dry with sarcasm.

The Doctor waves her off dismissively. "Not to worry! It might be wrong in almost every conceivable sense of the word, but there's still something to do here; I'm certain of it."

He takes off in a random direction, striding with purpose, tweed jacket flapping in the breeze. Amy follows after him.

"Absitively posolutely," the Doctor says, resolute. "There's something to do in nearly everyplace; it's simply a matter of finding out what."

He scans the landscape while they walk; this place is riddled with a feeling of déjà vu, nagging at the back of his head, but he can't quite figure out what it is, or why his time sense is pinging like that.

"There's something," he mutters. "Something or somewhere or somewhen or someone—"

"There's someone," Amy says, pointing up ahead.

The Doctor follows the line of her finger, claps his hands together when he sees the Someone up ahead through the forest. They're partially turned away, their head bent down as they look at something in their hand—probably a mobile device of some sort, they're all the rage in these millennia—but it's definitely a Someone, not a Something (or, for that matter, a Nothing; nasty little buggers, those).

"Right you are! See? There's someone! Maybe they can turn things around," the Doctor says, doubling his speed. "They'll let us know if there are any good revolutions to join or feuds to settle or give us directions to Neptune or a rock quarry or a good nearby ice cream place or oh my god that's Rose that's her that's Rose that's Rose Tyler that's oh good Heavens," he babbles in a sentence that somehow took on a life of its own.

Because it takes his brain a shockingly long time to catch up to his eyes and his mouth, because the closer they get to the Someone, the more he is able to triangulate, between the height and the species and that exact shade of bottle-blonde, who exactly that Someone is.

He doesn't even realize that he stopped in his tracks until Amy thuds into him from behind.

"Oi," she says, pushing him away. "Who's what, now?"

"That," the Doctor replies, pointing, but additional words fail him. Amy, with her inferior human eyesight, won't be able to tell the details from here, but as the figure turns her head, the Doctor catches sight of her profile, and he would recognize it anywhere, from any distance. Those eyelashes and that upturned nose and those sweetheart lips and suddenly he's remembering a revolution, and an extra trip here, and a stolen hug, and he thought the air tasted like one of the terraformed Keplers, he really did, but he's sort of stupid sometimes.

"That's Rose Tyler," he says, a once-familiar warmth blossoming in his chest.

Amy looks from him to the figure in the distance, arching an eyebrow in confusion. "Okay. Cool. Rose Tyler. Nice name. Are we gonna go talk to her, or—?"

"Oh, no," the Doctor interrupts, though he smooths down his hair and adjusts his jacket and bowtie all the same. "Most definitely not. That would be a bad idea. Very, very bad. Well, I mean, it's a good idea, but no matter how you do it, a poor execution. Any kind of in-person talking or interacting is out of the question. It would end quite badly."

"Like, ex-girlfriend badly, or time-and-space-go-boom badly?"

"Yes," says the Doctor absently.

Brow furrowing, Amy fixes him with a piercing look.

"Anyway, best to go before she notices anything!" the Doctor exclaims, grabbing Amy by the hand so he can pull her back the way they came.

"Really? You're just going to leave her here, all alone?" Amy asks, shooting a glance over her shoulder as they half-walk, half-run away. "You're not even going to say hello?"

"No, ta! Like I said, too dangerous. Already learned that lesson the hard way once, not in any great rush to do it again, and even if it would be lovely, I simply can't take the risk, not even to say—"

The Doctor screeches to a halt again and Amy crashes into him from behind, again, her body slamming into his with a force that would knock the air out of his lungs if he was paying attention. She staggers back, muttering under her breath, but the Doctor doesn't catch any of her words. He's too busy thinking.

He grins. He's still an idiot.

"What now?" Amy asks. "What's wrong?"

"Nothing," he says, eyes darting back and forth but not particularly registering anything in front of them. "Nothing's wrong, just thinking thoughts that are too big for thinking and walking at the same time. Know what I mean?"

"Not usually, no," Amy replies, but he can hear the smile in her voice.

The last piece falling into place, the Doctor turns back to look at Amy, finds her watching him expectantly.

"Sorry," he says. "I need to make a phone call."

He uses Martha's old mobile, finds it still buried in one of his bigger-on-the-inside pockets.

"Hello—?"

"He loves you," the Doctor says softly.

Silence greets him from the other end. He hears her quiet intake of breath, knows her mouth has fallen open in surprise. The Doctor can only imagine Rose is looking around, like maybe, if she tries, she'll spot this mystery caller lurking somewhere nearby.

He wishes he could see her face right now.

"He'll never say it," the Doctor continues. "That is, he won't say it until it's much too late. I'm sorry."

Still, nothing from the other end. But he doesn't let that stop him.

"It's all right if you ask him anyway; he needs to be put on the spot sometimes. Actually, he needs to be put on the spot for this conversation to even happen, so. Goodness, time travel is fun, isn't it?"

The Doctor sighs. His time sense murmurs in the background; he's pushing things. He needs to be careful.

"Look. The fact is, he's too much of a coward when it comes to this sort of thing. Always has been. Lived too long, seen too much, lost even more. I could offer all sorts of excuses, but in the end, it doesn't really matter. Some things do need saying. And he loves very deeply, if not very well. And I thought—"

Shaking his head, the Doctor chuckles. Rose must think she's speaking with a madman right now. (She is, of course, speaking with a madman with a box, even if she doesn't quite know it.)

"Well, I just sort of thought you should know," he says. "That he loves you."

The other end is quiet, still. He imagines she's thinking right now, or maybe realizing. When she speaks again, she does so in a tone that suggests she already knows the answer.

"Who is this?" she asks.

The Doctor can just make out the sounds of the TARDIS landing in the background. He smiles.

"Goodbye, Rose Tyler."