Nation, By Terry Pratchett

Nation, Terry Pratchett's latest novel for younger readers, starts promisingly: with the creation myth of an island people in the South Pacific – sorry, in Pratchett's alternative world, that's the South Pelagic Ocean. Then Mau, a boy of the Island people, returns from a solitary ordeal on a neighbouring island to find his whole nation wiped out by a tidal wave. He loses his faith in the Nation's gods – though they will keep jabbering to him in his head – and braces himself to deal with an influx of refugees from the tsunami, including Daphne, daughter of the heir to the British throne. The stage is set for a clash of cultures.

So far, so good: Pratchett's customary light touch enlivens his big themes of religion and imperialism, and the two main characters are likeable. But – and it's a big but – the story loses impetus as it goes on. The pace of events slows, and there are pages of over-explanatory dialogue and arguments in which characters carefully spell out their positions. If the second half was as good as the first, we'd be looking at four stars, not two.