Discworld is an extragavanza--among much else, it has billions of gods. "They swarm as thick as herring roe," writes Terry Pratchett in Small Gods, the 13th book in the series. Where there are gods galore, there are priests, high and low, and ... there are novices. Brutha is a novice with little chance to become a priest--thinking does not come easily to him, although believing does. But it is to Brutha that the great god Om manifests, in the lowly form of a tortoise.