Boy and Sistah, companions on the quest, depart their floating island in the vast expanses of their ocean planet, adventuring high up into the sky to the fifth level of the cosmos, famous for its cloud cities. There they meet busybody little people and the tall listeners to prayer, both residents of the gossamer cities.
Then on they go to the sixth level, in constant twilight, where they confront demigods and their own ambiguous size. And yet higher...