Back to Onrac
I spot a Sage behind the church., who I may have missed first time, who tells us that the shrine sank into the sea two hundred years ago. That would mean where we were wasn't the Sunken Shrine, I guess. The name Waterfall Cavern I suppose was the main clue...
He also lets us know that according to the story, there are mermaids living there. That's confirmed it - the Waterfall Cavern was a mermaid-free zone.
I realise now too that similar to Crescent Lake, I missed a part of Onrac first time - I bump into a names member of the townsfolk called Koppe, who saw a shining object fall. Somewhere near the waterfall to the north. Cool. Turns out we just did this quest without his clue again.
I promise I'm not trying to do this on purpose.
He says no-one believes him but he thinks it was some sort of mechanical creature. He must have good eyes, but that sounds like our Golem from the cavern.
At the end of that section too, there's a pier, with a girl stood next to what looks like a submarine. She immediately spots that we have oxyale - we must just carry all of our goods in display cases as we travel.
She says we are the ones they've been waiting for, and that we need to save the mermaids. She then seems to float away and evaporate into nothingness... Odd, but I guess prior to this, she was blocking off access to the submarine. She could have just stepped aside rather than evaporating dramatically, but it's her life.