What are there in the briefcase?

M: Are you tired of driving?
W: No, I’m fine.
M: Where is my briefcase?
W: Isn’t it on the back seat?
M: No, I don’t see it. All my important papers are in it.
W: You may have left it at the hotel. Should we turn around and go back?
M: Well, I guess we ought to go back, If you don’t mind.
W: I’ll turn off at the next road.