There are times in the diner — it isn’t the TARDIS, and they haven’t yet discovered what Her name is, so diner it remains — when Clara tries holding her breath for as long as possible.
If she’s dead, she thinks, she should be able to hold that breath forever, because she doesn’t really need it. And if she’s already dead, why return to Gallifrey? If she can’t hold it, then her lungs have limits, living limits, and she can still forget about ever returning to Gallifrey, because why let them kill her?
She’s aware of how irrational this is, and still she does it.
But the breath in her lungs never acts the way it’s supposed to. She can hold it for as long as she wants, which suggests that she doesn’t really need to breathe, which means she’s dead. But holding her breath starts to hurt after a while. The pain gets worse and worse, even though it’s never enough to make her stop holding her breath. And the pain tells her that she’s alive.
It isn’t fair, she thinks, and she laughs a little, bitterly; who ever said anything was going to be fair?
There comes a time, though, when the woman she’s traveling with tilts her head, looks at Clara, and asks, “Why does it matter to you?”
Clara starts to reply. “Because —”
The other woman — Ashildr? Me? Clara never knows what to call her, because the woman seems truly unknowable — smiles.
Clara starts to scowl; she doesn’t like being forced to look at her irrationality. She hates even more to be forced to look at its roots. But her scowl smooths into rueful acknowledgement. “You’ve got me.”
“Good. I wasn’t certain you’d let me catch you.”
There’s a moment of head-clearing surprise, and then Clara laughs. This time, it’s not bitter.
After some unknowable time of companionable silence, Clara tries to explain, at least as much as she understands herself. “When I went out to face the raven, I was terrified, but I needed him to not be terrified, you know? I’d been as mature as I could force myself to be, gave him all sorts of advice … what would it have looked like if I’d run from my own mistake?
“I mean, I couldn’t outrun death. What’s that American poet? ‘Because I could not stop for death, He kindly stopped for me.’”
The other woman nods her agreement. “You couldn’t. It wasn’t a choice left to you, after all your other decisions.”
Clara winces just a little, but continues. It’s important.
“But then he went and mucked it up. He always mucked things up,” Clara says, her face soft with remembrance. “He did it for me, I think. Mostly for himself, but a lot for me, and what he endured means that even if it was just a little for my sake … it was more than most humans ever have done for them.
“And once he grabbed me and pulled me into Gallifrey, any courage I had just … evaporated. He’d given me back hope, and—”
“ —as the cliche goes, that’s the most awful of curses.” The woman’s eyes are sad, and full of kindness. Clara can’t withstand the kindness; it lures her into asking the question she’s tried to avoid.
“What can I call you? Please don’t say ‘Me.’” Surprising herself, she puts out her hand, touches one of her companion’s. “Can’t I call you Ashildr? That’s the you I first met.”
For the briefest of moments, Clara thinks she sees fear in those sad, kind eyes, but then it’s gone. The woman looks up at the ceiling of the diner as she says, “I forgot that name, you know. By the 1600s, and despite all my diaries, I’d gone through so many names that I actually lost the name my mother gave me.”
Then she abandons the ceiling and looks into Clara’s eyes. “Yes. You can call me Ashildr. But there’s a price.”
Clara tries not to stiffen. “Sure. What?”
“Stop holding your breath. You have all the time in the world now, so just … breathe. Talk to me, sing, shout, curse, kiss … there are so many better things your breath can do than torture you. You are who you are, and it doesn’t matter — not to me — whether you are, technically, dead. Or unofficially alive.
“You are Clara. And I am, once again, Ashildr. Because you asked me to be.”
Her smile becomes very beautiful. And Clara’s breath catches in her throat, an altogether lovely feeling.
There’s nothing else she needs to say, but she says it anyhow, just for the pure joy of it.