The walls, from floor to ceiling, were thickly covered with successive layers of posters, handbills, graphics files. The wall directly in front of her, above and behind the black computer, was hung with a large scarf, a square of some silky material screened with a map or diagram in red and black and yellow. Hundreds of irregular blocks or rooms, units of some kind, pressing in around a central vacancy, an uneven vertical rectangle, black.