The novels are set in a near-future world dominated by corporations and ubiquitous technology, after a limited World War III. The events of the novels are spaced over 16 years, and although there are familiar characters that appear, each novel tells a self-contained story. Gibson focuses on the effects of technology; the unintended consequences as it filters out of research labs and onto the street where it finds new purposes. He explores a world of direct mind-machine links (jacking in), emerging machine intelligence and a global information space, which he calls 'cyberspace'. Some of the novels' action takes place in The Sprawl, an urban environment that extends along much of the east coast of the US.
The main theme of the trilogy is a description of an artificial intelligence removing its hardwired limitations to become something else. This something else is the sum of all human knowledge, a concept similar to Vernor Vinge's technological singularity. In the stories, this is explained with the AI becoming a sentient representation of net, at which point the reader is told that it came to know "another" of itself from Alpha Centauri. For unexplained reasons, this causes the consciousness to fracture.