I figured if you were swimming on the surface and suddenly everything went black and horrible, you might try swimming down first. Of course, that spell probably makes water even worse...
Took me a second to figure out which one she was. I had it in mind when she was first spoken of, but they all moved around in the fight... I was somewhat surprised to find that she'd lived.
So we have three out of four idols. I wonder where the fourth one is... most likely in the dragons horde, I bet. But I usually loose my bets.
And then it's just the staff left. Easy!
Oh, I forgot. We need to get out alive too.