The party comes across a nice hermit in the woods. He gives them food and lodging for the night. They awaken to his terrified screams. "East! It's east! Stop it! It'll kill us all!" The poor horror-stricken hermit dies thrashing in agony, one boney arm outstretched, his finger pointing to the east.
Like a Binding Oath Ring but it stops anyone under witness protection from revealing his or her true identity to anyone. I might make this into a submission one day.