"You agreed to come here?" This is clearly beyond Jamie's comprehension, probably mostly because he hasn't even begun to recover from his own sudden, unexpected arrival. "Where do you think you're supposed to be, then?" Because maybe if they can find out where this guy's headed, Jamie can figure out some way of getting home.

"If somebody's expecting you here, they wouldn't - they wouldn't just leave you out here, would they?" He sounds distinctly nervous at this preposition.