It's odd, the Doctor thinks to himself as he sits quietly on the steps at the far end of the console waiting for his companion to arrive, how very stale the air in the Tardis seems when she's not there. He smiles, fingers working over the smoothed ivory edges of the medical chip from a Mire's helmet before he palms it, taking in a long breath to consider it.

Stale and a bit metallic, he notes, like space itself.

He supposes it's all the travel, or maybe it's the static of home. One can never smell the intricacies of the place one spends most of their time, he knows, it becomes stagnated to senses, even the difference in temperature can become unnoticeable. The Doctor exhales in frustration, eyes lifting to the door as it opens.

The lights brighten just a touch as Clara closes those doors behind her and her boots lightly stomp their way towards a chair to drop her belongings into it. She laughs and begins a story about her day, as usual, and he smiles up at her, half listening to the words. Completely enraptured by the way she's altered the scent.

Maybe it's her shampoo, something clean with a hint of coconut; maybe it's her perfume, the airy scent of freshly bloomed flowers. Maybe it's her clothes, the cotton fibers woven together into a pattern of red and grey scratches that give off their own delicate aroma; maybe it's her breath, minty from a recent brushing.

Maybe he's thought too much on the smell of her lately, he ponders, and possibly every other detail since she'd re-entered his Tardis at Christmas. He couldn't help it; the Doctor was suddenly aware of how limited their time was... the notion always happened at some point, with all of his companions. Wonders if it were possible to take that time and stretch it out without consequences; wonders whether any would accept the sentence – because the Doctor knew how easily it could become a punishment.

He'd said so himself.

He feels the chip pressing roughly into his palm and he watches as she turns, her hands lifting in some erratic gesture, and then she laughs. It echoes just enough through the room to lift his lips in a warm smile and then her eyes meet his as her sentence trails and she slows, body stilling to watch him.

"You're not listening to me," she states.

His brow rises and his free hand points to her, all fingers bent slightly as he cranes his neck to respond, "Rattling off how much you love Jane Austen's writing again, because the students don't really appreciate it as much as they should, and how you'd like to take another trip back, which I'd be more than happy to accommodate so long as the both of you agree to not wander off again into the tall hedges of the gardens..."

"Ok," she interrupts with a roll of her head and a blush to her cheeks, "You're listening, but you're not hearing me."

He smiles, "I always hear you."

She offers a smirk and replies in amusement, "Now we both know that's not true."

Finger coming up to point, the Doctor supplies, "Oh no, it's definitely true – I always hear you; what I don't always do is listen."

Clara sighs and her palms lift slightly and then drop against her thighs in defeat before she starts to turn and then stops, drifting back to look him over, her eyes searching his before following through with a careful examination of his person. The Doctor fidgets, frustrated she can make him do so, because he knows she'll seek out that little thing he doesn't want to tell her and then she'll make him.

His left hand tightens its grip on the chip for a fraction of a second and that's when she sees it. Just that little flex of his muscles that shift the veins on the back of his hand and tighten the tendons in his wrist. That tiny tell in the way his eyes flinch at being caught, and she's got him.

"Whatcha got there?" She asks lightly, a bit of optimistic apprehension tingeing her voice as her body gives a small hop towards him, her hands coming together to fold in front of her lower abdomen.

The Doctor lowers his head and he can feel the breath of her exhale travel across the air between them. The disappointment in knowing this isn't going to be about some contraband yo-yo or some little treat he'd picked up for her, but about something she maybe doesn't want to talk about, but knows that now they will.

"Doctor?" The way she says his name is a question – quiet, pointed, and scared – and he smiles up at her in response, watching the way her eyes soften because she knows it's something that's been bothering him and it pains her to see him so pained.

How did he explain it again in a way she could understand. He'd been more than blunt before – there would come a day she wouldn't be around; there would come a day it would burn to breathe because the air would be stale and stagnant for far too long.

Taking a long breath of flower petals and sandy beaches, the Doctor asks, "Does it bother you, that your life is so fleeting?"

She smiles, eyes flickering away a moment in contemplation before her giggle bubbles up nervously. Then she tells him confidently, "I suppose the question is relative." She nods when he tilts his head. "Fleeting compared to what, Doctor?"

For a moment he doesn't answer, he merely considers the question. He considers the way humans have to constantly contemplate their mortality and how he'd had to once, not so very long ago. "When I was in Christmas, Trenzalore, before you arrived that last time – before I regenerated – I thought about how I'd lived so many years. I'd lived so very many years, Clara, and yet... and yet it felt so fleeting." He chuckled. "And even if you lived to a hundred, one hundred years compared to two thousand..."

Clara moved forward, stopping his words, and she nudged him aside, dropping into that small space beside him, leaning into him to curl her right arm around his left as she laid her head against his shoulder and told him softly, "That's why we try not to think on the span of time we get, Doctor. The number of days we have isn't what's important, it never is; it's more about what we do with those days while we're here."

He nods slowly, knowing he's said the same in the past; feels embarrassed for not remembering.

"Same goes for you, really, even if you live to be ten thousand, or even a few billion," she tells him on an amused whisper before asking, "What's in your hand, Doctor?"

Lifting his elbow against his thigh, he drops his left hand to lay it open against her right knee so she can see the chip lying there. He takes in her reaction, the curious stare to the sudden realization, and she glances up to meet his gaze, inhaling slowly as he tells her, "You could have it."

Clara smiles and she touches it lightly with her left forefinger, tracing around two sides of the edge before she takes hold of his fingers lightly, her thumb brushing over the space above the chip. The gentle unexpected caress tickling him just enough to send a spark of something like electricity up his spine and into his head and he bows to look at her fingers, remaining confidently wrapped around his.

"I don't want to live forever," she tells him sadly.

The Doctor nods, "I understand," then he laughs weakly, "Haven't I already proven how terrible that is."

Clara sighs and then explains, "You've proven how beautiful a long and bountiful life can be; how unquantifiable one being's love for life and the universe around them can be." Leaning into him again, she tells him, "What you've done with your time so far wouldn't be the reason I wouldn't want immortality; if anything it would be the reason to take the risk."

"Then why won't you?" He questioned curiously, his mind working over her words, putting them into a permanent slot in his memory to remember regenerations into his future.

Her cheek shifts with a smile and he waits for her answer as she thinks on it. He takes slow steady breaths of her existence at his side and he frowns because he knows it won't last forever. And then she tells him calmly, "Because you're not actually immortal."

And he understands her dilemma well; he understands her choice. He knows it's why she has the choice to begin with – he would one day have to learn to live in a world without her lilies and her jasmine and her coconut and her mint and her clean cotton clothes.

One day it would all be only stale... and a little bit metallic.