Avernum 3 Hintbook Corrections
The Orb of Thralni - The Complete Quest (Page 18)
Speak with Levy in Fort Emergence and then go to the Portal Fortress and speak with Seles. When ready, use the portal. You will be at the Arrival Platform (on the Upper Avernum map).
Leave the platform and go to the Subterranean Docks. Go to the Cult of the Sacred Item and row your boat in from the east. You will start at A on the Cult map. You will need a marble key. There are two of them in the fort, at the locations marked B on the map. Get one and pass through the door at C.
In the corridor beyond, you will take no damage if you approach the pools marked D and choose to wash your hands. Enter the treasure chamber and take the Orb of Thralni out of the box at E.
Go north and pass through the door at F. Try to use the portal at G. it will be powered down when you try to use it, and guards will appear. Kill them, press the button on the pedestal at H, and use the portal again to return to Upper Avernum.