...make sure you've got the Treasure Key (it's not the Scratched Key) before using the Baron's Key -- that's the usual mistake folks make.

there's a house in town with nothing but drudges....one of them has the cell key you will need

the house across the street has a bandie raver that had the dungeon key.

the empty cell with a halway behind it has the next key...

you'll have to hunt for a chest with another key, then on to the bottom

don't quote me, it's all from memory, but I think that's it