Clarke builds this novel with characters sketched lightly, involved in various actions spread across the solar system.

Intriguing or innovative aspects of setting, the details of times and places, are often summarized en route to the next event. The main character does not change significantly through conflict with a human antagonist, or through conflict with the environment, but Floyd is changed by unseen forces because of what he has learned throughout his life.

The "conflict" Floyd bespeaks is that of human civilization expanding its frontiers, not the change of an individual person responding to a personal crisis.

The personal experience Clarke has in telecommunications, aeronautics, and undersea activities helps him to keep his representative detail of space travel and the conditions on various planets and their satellites quite plausible. The story moves quickly to its end through many brief episodes and character sketches.