For the mage Kistandalius' shop, the only way to enter the back room is by paying the minstrel standing in front of the shop to recite some poetry, giving you a brief opportunity to loot. You can kill him, but since he sells charms and spell books, killing him for a single spell book doesn't make much sense.

For the potion dealer Walker, there is a trick to get into the back room, described here and here.


Dr Elrath's house is lockpickable until your second encounter with him. If you didn't use it already, there is a key by a rock or something just south east of the house (not sure if it works after he is arrested). After that there are a couple hacks to get back in;

FIX for the Missing Catacombs Portal

Teleporting Anywhere, via hex editor

If you stand at the north west corner of the house (or any building) you may be able to toss a teleporter stone into the front room.


or you can get the potions directly

Lost Items - guide and directory of inventory files