Jim's heart seizes at those particular words. Goddammit. At least he knows he's doing right by Bones even in Bones' own head, by being here. But there's so much pain in that, and his imagination's always been too good. He can see what it'll be like for Bones as time goes on, and he can see what it'd be like if he was the one who had to face this shitshow, too. It's one thing to face death at the end of a phaser, or a Klingon ripping your throat out with his pinky. A long, shuddery death with zero agency over yourself and considerable loss of dignity?

Fuck.

"Don't worry about me too much," he says quietly. "And I know that's near fucking impossible, because you'd care about other people no matter what. But you know what I mean. I'll be okay, as long as you let me be with you."