In the late 21st century, with the new ice age causing worldwide starvation, industrialized nations have condemned all private property. Citizens have been forced into huge tower complexes, and land is used solely for food production under the Bureau of Sustenance. Amos Benton and Jake Martinez, employees of the Bureau, are sent from Tower-7 to investigate interior damage and missing items taken from a sustainer pod near Dallas. It is finally decided that the incursions into the pod are due to hungry animals. Benton, recalling his capture and escape nearly three years earlier from a group of people still living outside, is not so sure . . .