I cleared the goblin camp and found the puzzle to go to the underdark. But before going there, I first wanted to clear the risen road (defeat gnolls, get Tyr's sword, visit Waukeen's keep and the Zent)
So after all this, I returned to the empty Selune temple, and I can't find the puzzle room anymore. I've been running in circles for hours it seems. On the mini map I tried to go to the lozenge "path to moonrise towers" as the underdark should be that path , but it's not the location of the puzzle. Actually it's just nowhere.
I'm going nuts. If someone could give directions to help find that room back, Shadowheart will send you blessings.