The sun is beating down on the tin roof of their bus as it lurches and coughs its way down the road. The Doctor, Rose, and Jack are on their way south, off the high plateau of Venezuela. They are still another four hours from the TARDIS, having been transported by an unfortunate bit of alien technology during the course of an adventure involving an alien cult, a missing spacecraft, and a particularly invasive strain of carnivorous plants.

Rose waves her guidebook like a fan and blows the sticky strands of hair off her face in defeat. She has given up trying to get the rusty, ancient bus window open. Instead, she fidgets, tugging at the hem of her shorts, and trying to get her legs up and off the cracked vinyl seat without much success. Every time she moves, the vinyl makes a wet, smacking noise as it parts with her skin.

Well, it is a bit hot, the Doctor supposes, shrugging a little in his heavy leather jacket and jumper and trying not to crowd her on the narrow bench seat. Unfortunately, as much as he'd like to make her more comfortable, there's not much that can be done about it. The window refuses to budge, even with the sonic screwdriver.

The previous night, they had been forced to camp out on the savannah at the foot of a tepui, after it became clear that running over the rough ground in the dark was considerably more dangerous than their pursuers. Jack had shrugged philosophically and fallen asleep on his rolled-up coat. The Doctor, however, had groused and grumped, kicking moodily at the rocky ground until Rose had taken his hand and suggested that the time would go quicker if he'd just sit still. And so he'd sat with his fingers still laced through hers, pointing out the equatorial constellations in a sky full of stars, until the sun came up and the howling of the Heliamphora faded away.

Of course, now when he makes the helpful suggestion that she'd be cooler if she'd just sit still, she arches an eyebrow and gives him a look full of disdain. He huffs in response and then looks away to hide his smile. Her glare is nearly a carbon copy of his, and that really shouldn't please him as much as it does.

Around noon, they pass through Santa Elena de Uairen and down into Brazil, and Rose has the pleasure of finally being able to use her passport. (The Doctor still thinks it is probably unnecessary—a bit of money changes hands at the border, just as they are waved through.)

They've been on the bus nearly two hours when she shifts beside him, curling until her head is resting on his arm, one knee pressed against his thigh. One sleepy hand lifts, drags the hair away from her face, and she snuffles, eyes closed.

And suddenly, the jacket and jumper combo starts to feel very warm, indeed.

The thing that's ridiculous is that it's just a knee. Just one little knee, resting against his leg; just the weight of one tired head against his shoulder, with just enough pressure to keep her stable as she sleeps on this hot, rickety old bus rumbling its way down the road. Just the slightest pressure of her bare skin against his covered, and for the first time all day, the Doctor's feeling the sweltering heat of this bus. And it's not the sort of overheating that can be solved by moving away—if anything, he thinks, more contact would be an improvement. He can see, in his mind's eye, how easy it would be to shift her around, to pull her legs up over his lap and her torso against his for a proper cuddle. He can imagine the sensation of the smooth round shell of her kneecap under his palm and the soft flesh of her leg under his fingertips, the taste of her hair under his lips.

(She is so very close to him.)

(She is not close enough.)

Surely she'd be more comfortable that way, him bracing her against every jolt and bump? And then maybe, this terrible heat, this friction caused by Almost but Not Quite, would dissipate, driven away by the more pleasant warmth of her body wrapped up in his arms.

His hands twitch slightly on his empty lap.

Two seats ahead, Jack turns away from the young woman he's been doing his best to impress and catches sight of them. To the Doctor's surprise, the expected leer never quite shows up—Jack's slow smile is more appreciative than lecherous, although there's a hint of the smug "I told you so."

The Doctor rolls his eyes and turns ever-so-slightly, so very careful not to disrupt his benchmate, to look out the window at the passing scenery. He already knows what Jack's opinion on this development will be, has already heard Jack's interpretation of nearly every one of Rose's habits, having been subjected to numerous one-sided discussions from the well-meaning but clearly delusional Time Agent.

In any case, he doesn't need Jack to give him guidance here—his palms are still tingling with the need to cup Rose's patella, among other things. It is as though she has completed the circuit, and electricity is moving between the two contact points, knee and thigh to head and arm. The resulting heat spreads, arm to chest to hearts, thigh to hips to groin, until the need to touch her becomes unbearable, overwhelming, insistent.

He presses his hands down, pushing the rough denim into his thighs.

The part of him that is old, so very old, wants her to be happy. Wants her to be safe. The part of him that is young (and isn't that amazing, that part of him is still young?) just wants her, wants to have her, wants to keep her. Wants to love her.

(That's also the part that wants to drop-kick Mickey, Adam, Jack, and all the rest of their ilk into next week and leave them there for good measure.)

But that's not his role. He is the teacher, the better-than-a-boyfriend companion, the guide. He might be allowed to take her farther from the human race, but not further; it is an important distinction, and one that he'd do well to remember.

Against his shoulder, his girl gives a sleepy, muffled snore, and he smiles, even as his hands close into fists.

It is enough, he tells himself, to sit here by her side. It is enough to struggle silently on her behalf, to endure this bizarre torment for her sake, because the one thing he will never do is place the burden of his desperation on her shoulders. Whatever he is now is a thing too broken for the likes of her.

His fingernails bite into his palms.

When her clumsy, sleepy hand finds the edge of his leg, it comes as a bit of a shock, and he has to stop himself from jumping at the contact. He can only stare as her palm drifts up and over his thigh, higher and higher until she finds his hand. The grip of his fist releases as she threads her fingers through his, her thumb softly stroking the inside of his wrist in a way that she'd never do while fully awake.

She snuffles into his jacket and mutters drowsily, "S'hot in here."

And just like that, it's over—crisis averted. He should have known—holding her hand is always enough to tip the scales in favor of sanity, even when she's the one driving him crazy. Really, he shouldn't find it so surprising.

He gently brushes his chin over the top of her head. "Yep."

For the moment, at least, this is close enough.