So I'm back at Erothin Fortress and must fetch the . I have no idea what room is considered his chambers. The red marker points to a shallow recess in the wall covered by tapestry, close to the end of the table. This is likely a misplaced door marker meant to be hidden. Where is the object that is needed? It's not at the desk in the throne room, or the room with tables arranged in a circle, or in the bed chamber high above and to the East.

Check for some levers in the bed chamber.