Problem restarting mercenary difficulty in a higher level game.
Alright, so I'm halfway through, but I still need to do the mysterious level for Mercenary (I didn't kill ???). So I decided to pay that difficulty a visit, and do some side quests that have Big Chests as a reward (I haven't done Eva's there, for example.)
Anyway, it loads up normally, but then I start at the siege of Greylin Beach (WTF) with drevin as a 7th character in my party (at level ~75

). The rest of my party is there, but when I click on them the camera floats to the brownish haze over the sae and I can't see or move them (save the 2nd character, who starts on shore with me (so I have 3 characters, me, #2, and Drevin.)) I can walk through the entire act I area but all the monsters are already killed, all the cutscenes have already happened, etc. Then, when I get to the area with the Rust Guard that's supposed to get frozen by the Morden mages, the cutscene doesn't happen. I can just walk past the statue and into the temple. I can't pick up the Aegis (though I can highlight it), and the Rust Guards just sit there crouched and ignore me.
Anyone have an idea what the hell?