This alternative history is based on the assumption that the Great Plague of the 1300s that decimated Europe's population was much worse, and that it in fact led to the extinction of almost all of Europe. It is not at all plausible as history, just from that single premise: Robinson readily transfers developments from Europe to Asia, despite the fact that nothing close to those developments happened spontaneously in our own history during the long centuries when Europeans were minimally in contact with Asians.

The novel is told in ten parts, spanning about eight centuries. Each part stars two major characters, whose names always begin with K and B, along with some important minor characters, whose initials are similarly echoed across the chapters. Most parts concern a key development, but usually things go all wrong and everyone dies and they have to be reincarnated and try again. The development is often technological, but it is just as often philosophical, with characters striving to create what we think of as 20th century liberalism.

As a result, the book at times is very preachy. Nevertheless, Robinson doesn't mind contradicting himself. The book ends with a liberal modern scientific thinker discussing and rejecting reincarnation, while the reader can't help but notice the recycled souls unaware of their own previous lives.

One of the developments is the invention of analytic geometry and calculus, spelled out in some detail in the fourth part, "The Alchemist".

Educational book