[If Kaveh chooses to turn and look now he'll see Alhaitham going through a series of expression, each one displaying more of his discomfort than the last. Kaveh of all people would know how terrible Alhaitham actually is at having to try and explain himself in a way for others to understand, when it comes to things like this. Then again... Kaveh isn't exactly just some other person. He used to be the one who'd understand Alhaitham easily, who'd pick up on everything without needing to be told twice. This gap that exists between them now as adults has always been something he'd found difficultly navigating around, and being here hasn't really changed much of that either.

But this isn't Sumeru, where they had other people or other things to fall back onto. Here, they only have each other, and if they lose that...

More than anything, it is perhaps that particular understanding which drives Alhaitham to speak, because there is the knowledge that neither of them truly have anything else in this place they'd been sent to without warning except each other.]

To have you understand would require me to thoroughly understand the matter itself first. [He gets the words out, and there's no denying how hard it is to even spit that out into the open, this indirect admission that he has to make.] And that is... something which I have not been able to do.

[It is a lot, for him to admit this out loud. But like it or not Alhaitham already has little people to talk to back in Sumeru, let alone this place so far away from Teyvat and everything else they've known and grown up with. Kaveh is the only one, for better or worse.]