We’d reached the perimeter of the legal slum, and the megalithic immensity of the twin skyscrapers loomed before us. Concreting had been completed to three-quarters of their height, but there were no windows, doors, or fittings on the unfinished buildings. With no flash or reflection or trim to relieve the grey massiveness of the structures, they swallowed light into themselves, extinguished it, and became silos for storing shadows. The hundreds of cave-like holes that would eventually be windows allowed a kind of cross-sectional view into the construction—an ant-farm picture of men and women and children, on every floor, walking to and fro, upward and down, about their tasks. At ground level, the noise was a percussive and exciting music of towering ambition: the nervous irritation of generators, the merciless metal-to-metal zing of hammers, and the whining insistence of drills and grinders.