mantis,
A note for the Lexicon, if you haven't gotten it before: When Severian is told (at the House Absolute) that Dr. Talos and his company are in the Green Room, they are taking part in a tradition that goes back to our time and before. In theatrical parlance, the Green Room is the room (regardless of color) in which the actors wait before going on stage.
Severian's surprise that it isn't a room at all can therefore be excused.
-viz
(david_lebling at avid.com)