Raldo:
Good! I shall go and look at the other magic fields, meanwhile you should to to the Dwarven Village. It is likely that it is their next destination.
Ask the Elder Filaur of the Dwarven Village about the location of the magic field. I suppose they sent the succubus flock to break down the magic field. Keep watching the place and when the evil creatures show up, kill them all! Perhaps this is the last chance! If the magic field is destroyed as well, 'the thing' will revive!