He'd forgotten how deceptive distances could be in the desert. He's been walking for a tediously long time, occasionally slipping a bit in the sand, before the light grows any brighter. Finally, he crests a dune and finds himself looking down at a small cluster of canvas tents. Flaming torches are spaced evenly around the perimeter. There's no activity in these small hours of the night, but the flap on the largest tent is open, spilling warm light across the sand. He skids down the side of the dune, kicking up yet more sand (he's beginning to hate sand), and cautiously approaches.
The woman inside the tent is sitting on a crate, writing in a notebook. Her face is turned partly away from him, profile half obscured by golden curls. The Doctor's breath catches in his throat.
She chews the end of her pencil, jots down something else. Not her TARDIS diary, he sees now, but a field notebook with pale green pages. "About time you showed up," she says absently. "Just a minute, sweetie, I've got to get this down before…"
The Doctor coughs, and River looks up abruptly; for a moment, she goes very, very still. Then her mouth curves up softly. "Well, aren't you looking spectacular."
"River." Have you seen me before, did you know this would happen— How many times does he have to come to terms with saying goodbye to her? He'd dipped back into her timeline compulsively after Darillium, finally parted with her data ghost on Trenzalore. He can't do this again. He can't. "I'm not staying."
"Don't be ridiculous." River sets her notebook aside. "You must have come here for a reason."
"I really didn't."
"It's okay. I'm sure you'll figure it out eventually."
"It was a coincidence. I landed back over the dunes, thought I'd take a walk."
"In the desert. At night. Dressed like that." Her eyes flick up and down, taking him in. "Want me to guess? Newly regenerated, right? You're wearing that body like you're not sure it fits. Needed a familiar face? Or something?"
The Doctor looks away. "I wasn't alone when it happened. Cl— Someone was there."
"But she isn't with you now."
"No." He doesn't want to talk about this. "What are you doing here?" he asks instead, nodding over at her notebook.
"Shepherding some students on a dig. Looking for evidence of the Alexandria Key, actually. I don't suppose you'll tell me where to find it?"
He snorts. "That would be cheating. Even if it did exist."
"Using the resources available to you isn't cheating." She eyes him thoughtfully. "Besides, rumours of a time traveller visiting the Library of Alexandria before it burned and scanning the entire contents to a data drive? Who does that sound like?"
"You?"
River pushes some papers aside, uncovering a vortex manipulator. "Don't think I haven't tried. That whole time period seems to be locked."
The Doctor shrugs. "Well, it wasn't me. Or if it was, I haven't done it yet. Can't help you."
River rolls her eyes, and he finds himself smiling at her. Maybe this is why he's here. He drinks in the sight of her: her bright, riotous hair, the crinkle at the corner of her eyes when she smiles back at him. She's the same as he remembers, and no matter how much he changes, it makes no difference to her. As far as she's concerned, he's still him, and they're…
Together. Alone, possibly for the last time, in this little tent in the middle of the desert. Well, alone in a tent surrounded by sleeping graduate students, actually, but that's a lot less off-putting than it ought to be; he and River have rarely been able to choose their circumstances. The Doctor swallows, feeling his hearts starting to beat faster. Among other autonomic responses. Now there's something that hasn't happened in a while.
River gives him a long, steady look. "Well, I'm sure I can find something else for you to help me with. I'm certainly not letting you leave like that."
He glances down—he hadn't thought it was that obvious—only to find that his coat is, in fact, covering him decently. He raises an e