After the wizard tells you about it, go to the Inn. If you go during the day there will be
a scene between the couple who own it (weird). Make sure you go in after 22:00; it will be
open. Then there'll be a scene where you find out the guy has had the crystal ball there
at the Inn for a while. If I remember correctly, the wizard appears a second later, you
end up going to his house, and that's it.