The novels are set in a future several hundred years distant at a point where the nations of Earth have expanded into and filled the Solar System. Various planets, moons and asteroids within the Solar System have political, religious and geographical affiliations similar to those on 1980s Earth. Many events in the series parallel modern-day situations; for instance, Mars is controlled by the countries formerly comprising the Middle East, and has the largest supply of iron, the primary fuel in Anthony's universe. Ganymede parallels Cuba, and has a Communist government allied with North Saturn's, which corresponds to the Soviet Union. A "Missile Crisis" is an event in the series; many other such correspondences abound.