At the Cape Sorrow there is a strange spiritual symbol containing several gems. Naturally, when you open it, you get stunned for 3-4 rounds, and a pack of cursed undead appears. They immediately begin to beat you and unless you're a real superhero, they kill you before you are able to move again.
However, if you stand right behind the spiritual symbol (to the NW side of it), open your inventory, take a powder keg and drop it onto the symbol (the symbol must be highlighted under your cursor when you do so), then happens the next: you get stunned, the keg drops near the symbol, undead appear, but! - they begin to move in the wrong direction (not towards you) and they mostly ignore you as a target. You press "SPACE" until the stunning effect is gone, then you close your inventory and run. At this moment undead begin following you as they should, but you are at a safe distance now, so you can kill them without any serious difficulties.