We must locate Flayn, and soon. Let's gather all of the information we can around the monastery. Surely someone must have seen or heard something.
Gather clues about Flayn by talking to different people throughout the monastery. If someone seems suspicious, you should check their room or other places they might spend time.
  1. Accept the quest from your house leader.
  2. Gather information about Flayn.
  3. Report to Dimitri.
I agree that Professor Jeritza's behavior is odd. We should ask him directly. I expect he'll be at the training grounds or in his quarters.