Terry Pratchett's 13'th Discworld novel.

Main/Reoccurring Characters:

Lu-Tze/Monks of History: Poses as a gardener throughout the story, ensures that history happens correctly.
Brutha: The protagonist, and most recently chosen prophet of the Great God Om. A lowly novice with an uncanny memory and rather black and white view of the world.

Deacon Vorbis: Cheif Exquisitor, the single antagonist (in rather rare form for Pratchett, who usually has some faceless group, demon, entity from the Dungeon Dimensions or whatnot as an antagonist). Vorbis is hatching a plan to take over the neighboring country of Ephebe, and has tricked Brutha into helping.

The Great God Om: The god of Omnia, or at least, he used to be. Between now and his last coming, it seems his followers believe more in the church of Om than in him, so when is 3000 year appearance is due, he, to his surprise, finds himself incarnated as a tortoise, a small god, with only one actual believer left; Brutha.

Cut-Me-Own-Hand-Off Dhblah: Not an especially important character, but a distant cousin of a familiar Ankh-Morpork Merchant...

Didactylos: A philosopher of Ephebe, one of many, and not one of the more popular ones. Put forth the idea that the Discworld is actually flat and round, Carried by four elephants, who, in turn stand on back of the great cosmic tortoise.

Urn: Didactylos's apprentice. Has a number of practical inventions of his own, including a curious device that makes a boat move using fire.

Published by HarperTorch
Copyright 1992, Terry and Lyn Pratchett
ISBN: 0-06-109217-7