The story describes a world in which most of the human population has lost the ability to live on the surface of the Earth. Each individual now lives in isolation below ground in a standard 'cell', with all bodily and spiritual needs met by the omnipotent, global Machine. Travel is permitted but unpopular and rarely necessary. Communication is made via a kind of instant messaging/video conferencing machine with which people conduct their only activity: the sharing of ideas and what passes for knowledge.