Martin set the lifeboat down carefully, with all the attention one usually exercises in a situation where the totally unexpected has occurred, and he and his two companions sat and stared in awed silence at the city a quarter-mile away. He saw the dull, black walls of buildings shouldering grimly into the twilight sky, saw the sheared edge where the metal city ended and the barren earth began ... and he remembered observing, even before they landed, the too-strict geometry imposed on the entire