[ It seems like Yona is doing everything in her power to convince Zack that she's fine, which really only makes him more concerned, but he isn't going to push it. If she ends up collapsing again, that'll be a different issue, but they don't know each other well enough for him to get too pushy about it.

She does agree that they should spread the word, so that's something. ]

Oh! [ He shrugs. ] I mean, I didn't really do anything. I'm just glad you're all right.

[ Speaking of things that are out of the ordinary, though...

Zack takes a moment to look around them, as if studying the tunnel walls. ]

Have you been hearing that? [ Thump-thump, thump-thump. ] It's like this pulsing noise.