Witcher 1 help - Wraiths of Quiet Hamlet adventure
 

I've beaten the main game - very great game (9.5/10 I'd say). And so I started playing the adventures (mods) that came with the Enhanced Edition.
However, in one of them, as the title suggests, I can't figure out to what do next.


I've nearly finished this adventure, Wraiths of Quiet Hamlet, I can tell.
I've done everything and I've talked to everyone, they don't have much new to say anymore. I've talked to the son (who is a wraith). I've gone to the place where the echinopses grow, and I've seen floating wraiths - can't talk to them, though.

I've looked everyone for a walkthrough for this adventure in German, English, French and in Polish. Nothing. At all.

My question now is this:
Have any of you played through this adventure and can guide me to what to do next? Thanks in advance :)

/aries323