Ugh, I think that I've hit a glitch or something. I'm on The Watergod's Altar, and I have to find the 5 pieces of slate. I have wiped out the dungeon, and it says that I only have 3 of 5. I have opened every single chest that I've come across. I've even used a map, both online and off, that shows the exact location of all 5 slabs. I systematically went to each spot, and those chests have ALL been opened. I haven't dropped or sold any of them. Very frustrating, considering that it's a mandatory quest.
I'm considering starting a new game (arrrrgh), but if I get to this quest and the same shit happens again, I might join Al-Qaeda.
Just ugh.