Terminal World

Terminal World is a science fiction novel by the Welsh writer Alastair Reynolds, published in 2010. It is a standalone book rather than part of any of his series.

The setting is an unspecified distant future in which human civilisation is largely confined to the city of Spearpoint, which sprawls across the surface of a vast artificial spire made of a nameless black material. Spearpoint and the surrounding country are divided into zones, regions of space-time that exist at different energy states. Zones close to the spire are small enough to mark out particular precincts of the city, while the ones further away grow much larger, and each zone will only support technology of a particular kind. People need periodic drug treatments to survive outside the zone they belong to, and Quillon, a pathologist, is forced out of his when his circumstances change. The book follows his journey away from the city, through a landscape in which the rules of what can work change from one district to the next.

The novel sits at the harder end of Reynolds's writing, where the central ideas are engineering and physics rather than space travel. A city that has to live with zones of different physical law allows for airships and industry in one direction and something closer to magic in another, all within a single continuous world.