This guide refers to the following edition: Mezieres, J.C.; Christin, P.; Tranle, E. Valerian and Laureline: The City of Shifting Waters; Cinebook, Cantebury, Kent, 2011. Kindle AZW file.

Mezieres' and Christin's Valerian and Laureline: The Empire of a Thousand Planets takes readers on the next mission of Valerian and Laureline, two space travelers who work for Earth's Spatio-Temporal Agency. Valerian is the leader of the duo, but Laureline is also capable, intelligent, and determined. This novel opens as the two travelers are about to arrive at Sytre, the capital city of an extensive galaxy. As far as they know, they are the first Earth travelers to reach the galaxy, which has yet to create time/space jump technology.

Valerian and Laureline stop in a marketplace upon their arrival, and Valerian purchases Laureline a watch that captures her attention. A short time later, they get their first look at a member of the Enlighteneds, a group who has a great deal of power in the city. The Enlightened sees the watch and asks Laureline about it. When she says the watch is for tracking time, the Enlightened walks away and several of Syrte's people laugh. Later, Valerian and Laureline learn that the people of Syrte have an ingrained sense of time, and do not need a watch. They also learn that one of the Enlightened traded the watch at the marketplace years earlier.

They are briefly kidnapped and discover an abandoned power plant and scientific lab. Upon their return to the city, Valerian becomes convinced that there is something wrong with the galaxy's leader, Prince Ramal. He and Laureline manage to sneak into the palace where they have yet another encounter with the Enlighteneds and find that Prince Ramal seems interested only with the next social event.

A merchant named Elmir reveals that the Enlighteneds have forced an end to science and exploration, inserting themselves as rulers of the galaxy. Elmir has gathered a group of people willing to fight the Enlighteneds, and they ask Valerian and Laureline to lead them. The battle is short, thanks to the technology Valerian within his spaceship.

On an asteroid, Valerian finally has a face-to-face meeting with members of the Enlighteneds. He learns that they are from Earth, sent to find a habitable planet centuries earlier. They have become immortal, thanks to a substance mined on the asteroid. Their hatred of Earth – for putting them in this situation – has driven them for centuries. Now, realizing that Earth's technology is far superior and that their hope for revenge is futile, they all commit suicide.

Valerian, Laureline, and Elmir return to the capital where they discover that the people have begun a revolution. Valerian points out that the Enlighteneds would not have been able to take control of the galaxy unless there were underlying problems. Agreeing, Elmir sets out to join the fight, hoping to be part of the new government and telling Valerian they would be open to a trade agreement with Earth.