Now NASA’s ingenuity had borne amazing fruit, and the streets of Washington were lavishly bumped and measled with martian settlements. Slums of compacted dirt, all glue and mazy airlocks, climbed straight up the walls of buildings, where they clung like the nests of mud-daubing wasps. There were excavation hills three stories high near Union Station, and even Georgetown was subject to repeated subterranean rumblings.