Shards of Light

So, there's a certain black stone that's responsible for the appearance of strange shadowy creatures. It's the same type of stone that was discovered in Tep's sarcophagus. It's also known that the stone inhibits resurrection. As to the cause of this, that part remains unclear. At which point the matter was brought to my doorstep.

What in Tep's name took you so long! Here we are with essentially the same problem - our men are not resurrecting, and their souls are cursed, unable to find their bodies! Now they wander the halls, attacking all who come near!

In the past these sorts of things would appear only when they had no body to return to, but this is a very different phenomenon. The bodies are there, but the souls simply cannot find them!

Listen, we need to study those lost souls. What I wouldn't give for a Sparkton Pack right about now! But in its absence, we'll need to make do with a cruder method.

Each soul contains a shard of light that's infused with holy magic, even cursed ones. Go kill some of the ones up ahead and gather several of their shards. I need to study them immediately.

It's just as I thought. With only one sample I was able to figure out this dreadful phenomenon.

What? Why didn't I just ask for one sample to begin with? Because most of the specimen are bad, and I didn't want to waste loads of my time explaining the difference! Instead, we've let the law of probability work for us - typically, one out of every five is the right one.