During the preparation for the fight between Minthara and the tieflings, I was given a quest to look for Doni and send him to the cave. He was standing in front of the stone door to the druids' sanctuary, and when I got close to the door there was a voice yelling to "go away". But the only dialogue I could get from Doni was a grunt, with no option to say anything to him, and clicking on the door just got my character saying "locked from the inside".
If it makes a difference, I'd done both the quest where you save the kid from the harpies and ask Doni to show you the hatch to the cave, and the shadow druids questline that ends with killing Kagha.
