answer: #Person2# is gloomy because #Person2#'s dissertation is lost. #Person1# helps #Person2# find it, so #Person2# doesn't need to write a new one.
documents: #Person1#: Why do you look so gloomy? What are you looking for?
  #Person2#: My dissertation. I put it somewhere last night and I can't find it now.
  #Person1#: Did you finish typing yesterday?
  #Person2#: Yes, I kept on typing it until midnight, but it is lost.
  #Person1#: Don't worry about it. It must be somewhere in your room. Let's see where you put it. Have you searched your drawers and the desk?
  #Person2#: Yes, but there is nothing inside the drawers or on the desk.
  #Person1#: How about the shelf?
  #Person2#: I've searched everywhere. Where on earth did I put it?
  #Person1#: Don't get upset over it. At least you have another week to go.
  #Person2#: I have been working on it for a whole month and it's too late to write another. Just think of all my hard work that goes for nothing. How could I do such a thing?
  #Person1#: Cheer up! What I meant was that you can find it sometime during a week. There is no need to write a new one. Oh, what's this? Is this your dissertation?
  #Person2#: Let me see. Yes, that's it. Where did you find it?
  #Person1#: You'Ve put it among these journals.
  #Person2#: My poor memory. Thank you very much.