Got to the end of Ethel's cave, where there's a big empty room and the girl in the cage in the middle. Thought some enemies/Ethel herself would jump out once we came in, but nothing happened. Thought maybe it would happen once we pushed the button on the other side of the room, but nope. Instead, we just freed the girl, who we couldn't talk to, and then proceeded to the obvious hey-you-beat-the-big-bad-have-some-loot room.
I suspect this bug may have had something to do with me sending in my invisible imp to scout for us first, since as I understand it, a cutscene was supposed to happen upon entering. I'll attempt to load an earlier save later and walk in first to see if that fixes it.