[She's lost count of how many times she's cried on Alina. One more isn't going to harm anything, not with as close as they are at this point. She crumples completely, all of the fear and anxiety she's feeling pouring out of her in tears. She winds up hiccuping in between sobs, and she just sits there with one hand holding Alina's and the other pressed over the hand that's pressed over her heart. There's a steady beating there now, and it races faster and harder as Clara works herself up to becoming nothing but sorrow and tears.

It's hard not to feel like she's feeling sorry for herself, and she couldn't possibly hope to explain that isn't the case. She's finally grieving the inevitable loss of the Doctor, though she hasn't even begun to touch that part of the story yet. How could she, when Alina is trying so hard to make her feel truly alive and that she's capable of making such an impossible choice? ]

I can't do it. [She manages to get out through her sobs.] I can't -

[Her entire body shudders as she tries to force out the admission. Her betrayal, the thing she's done right before coming back to the station.]

I can't risk losing him completely. Not after I had to force him to forget me, everything about me.

[Meaning this time here is all they have left. This is it, after this is over she'll go back to an existence where the Doctor doesn't remember her. He'll know that someone named Clara exists, that they had certain adventures together. But he won't remember her, and all she can do is relive the moment in the diner when she looked at him and realized he didn't know her at all. She had sacrificed her relationship with him then for the good of the universe, and for his own good. But she isn't sure she could do it again, that act of selflessness proving to be a heavy burden for her to try and rationalize now that she's here with not one but two Doctors.]