orichalque

Hi,

I finished Avernum V but I am stuck in avernum IV;

I can't pass the barrier of fort emerald and the door of fort spire is closed. I don't find any other way to find the "demonslayer" or to go to the abyss".

I think I have killed all the "monsters" of the great cave and around and made all the possible mission.

Any advises?

Thanks a lot!