Son of the Tree begins with the arrival of Joe Smith on the planet Kyril, so distant that Earth is but a myth. Kyril is dominated by a religious aristocracy called "Druids", who rule over the five billon commoner "Laity", and who control worship of the "Tree of Life" – a huge tree with a trunk five miles in diameter, and height of twelve miles. The Druids are xenophobic, and consider Joe to be ...