High Priest Gregory:
Stones of commune and Tablets of Vision have a magical mutual attraction. You can use this force to locate the Tablets of Vision.
Put simply, when you have a Stone of Commune, the location of the corresponding Tablet of Vision will appear in your mind. Once you find the next stone, you will see where to find the next tablet. This is the path that Hindemith has chosen, and you will likely find him there.
This process will become clearer to you as you move along. Now, take the Stone of Commune I gave you and find the first Tablet of Vision south of the Tower of Insolence!