Wicker Worship

Hail, traveler! You look like just the sort who might be able to help me out with a predicament! It's my son Edwin, you see. We were travelling through Drustvar to ply our wares when the damned fool ran off to join some cult here in Autumnvale! Since then we haven't seen a trace of him, and the brown-robed loons won't speak a word of his whereabouts! Could you see if you could persuade them to talk? His poor mother is worried sick!