You play within one huge fortress, through several chapters of the story, and you can see the fortress on the map the whole time. But - only certain areas are accessible at a time. You begin as a newly-arrived soldier, and have to battle your way through the destroyed outskirts (outside the fortress. Then you return and seek information.
One Quest for example is that a king (yes, there are several kings within this huge fortress) has been poisoned. So far you have had access only to the part of the forteess where the soldiers live, and the area before the entrance, and the entrance itself. Now you've got access to the part of the fortess wherethe kings and their courts live.
One alchemist you asked about herbs (in connection with curing that poinson) tells you about a merchant in another area you haven't heard of before. You've got to see him and talk to him.
Now, you've got to check every staircase you know of to see whether it leads into that new area. One eventually leads into what I call the inner court of the fortess where you've never been before. There is the merchant.
With that deed - finding the entrance to the inner court - you've more or less "unlocked" that area for you, and can access it now from that on from almost every staircase. But only from then on, after you've actually found the right staircase or entrance.
That's it what I had meant.
When you find a big kettle of crazy, it's best not to stir it. --Dilbert cartoon
"Interplay.some zombiefied unlife thing going on there" - skavenhorde at RPGWatch
