on 17 May 2001
This brilliant story is set in a two-dimensional universe, with which a group of the author's computing students enter into contact. They follow the adventures of Yendred, who lives on the planet Arda, which is of course a circle, not a sphere. He lives on the western edge of the single continent and decides to set out in search of the wisdom of the East. On the way he visits a scientific research institute and a centre for the arts, but neither gives him the understanding he thirsts for. The science of this flat world is worked out in great and convincing detail; there is even a periodic table of the 2-D elements. Eventually he reaches the highest point of the continent, the watershed between West and East, where he finds a shrine in the form of a rectangle - the two-dimensional equivalent of the cuboid Kaaba at the heart of Islam. I don't want to spoil the surprise that awaits readers when he gets there, but I can reveal the secret that beneath the two-dimensional surface of the story there is hidden a Sufi allegory, hinted at by the many Arabic words in the language of the flat world. This deeper level makes the book unique in science fiction. It leaves you seeing our three-dimensional universe through new eyes. My one complaint is that in the second edition the author felt it necessary to explain in an introduction that it was fiction; he had been pestered by too many readers asking for technical details of the computer settings that gave access to the Planiverse.