Before NATION, I only knew Terry Pratchett from the DISCWORLD series and GOOD OMENS. NATION is completely different, and very good.
Mau is between boyhood and manhood when he becomes the sole survivor of a tsunami which destroys the population of the island Nation. The tsunami also shipwrecks Daphne, daughter of the colonial British governor of another island. Mau and Daphne learn to communicate and offer refuge to other survivors who straggle onto the island. Together they all rebuild the Nation.
Part alternate history, part theology, part sociology, and all good storytelling.