How does the author structure the novel, Lord of the Two Lands?

The novel opens with Nectanebo's spell, then shifts to Meriamon's adventures with the army many years later. At the very end, the journey through the desert, the sandstorm, and the miraculous rain lead to Alexander's transfiguring visit to the oracle. The focus thus goes full circle, from magic to clamorous, mundane events, and then back to magic and mystery at the end.