Finding himself inside someplace metal and humming is only a milder kind of shock to Cor. This, at least, isn't quite as surprising, though he keeps looking around as if he's expecting some kind of enemy to pop up any second.

"...what do you mean by 'a whole other world'?" Because he doesn't think that Prompto would be joking (much) about that kind of revelation. "...and is there a place to sit and chat?"