[quote name='007']Yeah, the likely problem is that you're either overlooking, or are unable to find the 'mall' stronghold.
It *does* appear on the map at the mall, but the activation point is actually INSIDE the mall. Took me a while to figure that out... it's poorly thought out.[/QUOTE]Yup, that was the problem. The Ultor stronghold didn't appear on my map until I set the map to show only strongholds. It didn't show up on the default "show everything" setting.
Once I finished the mall stronghold, the final mission icon appeared on the map, so I guess that's what I was missing.
I don't think I ever did the police station mission, either, PhrostByte. Now if I could only remember where the police station is.... Well, I'll find it. I finished the game, but I'll still be trying to get a few more achievements from it.