The Glitter Band is made up of about 10,000 habitats each with tens or hundreds of thousands of inhabitants; they are more or less autonomous and each has its' own eccentric society ranging from art collectives to "voluntary tyrannies." The set-up resembles Ancient Greek city-state democracy, with a federal police force, the Panoply, that polices every citizen's access to e-democracy.
The opening chapter introduces Prefects Tom Dreyfus and Thalia Ng as they investigate an electoral anomaly in one of the habitats. Having read Century Rain, a Reynolds novel separate from Revelation Space and an experimental detective story, I wondered if this would be a sci-fi police procedural as this is the initial tone. However, the plot soon widens to take in larger sci-fi concepts and conspiracies. Reynolds' characters are often called upon to make moral choices, and this is taken to extremes in The Prefect as Panoply agents are forced, over and over again, to decide whether to "euthanise" individuals or entire habitats to protect the entire Band; in parallel, similar choices have to be made regarding the treatment of senior prefect Aumonier who is infected by a parasite of unknown origin.
There's a traitorous-senior-officer subplot which is well executed if a bit predictable (I'd love to read a political novel in any genre where a senior officer wasn't plotting to overthrow the commander). On second thoughts, having lived through the Blair-Brown years here in the UK, perhaps this is simply a reflection of real life. And of course let's not forget Klingon culture where it is the duty of the second-in-command to plot to overthrow the captain.
This novel stands up well against the rest of Reynolds' work, full of memorable characters, plot twists and revelations, and thought provoking moral dilemmas on all scales. The Revelation Space universe has now reached escape velocity and left Earth's region of influence - as a result you should definitely read the earlier books before this one (starting with Revelation Space itself), as factions such as the Conjoiners, Ultras and artificial intelligences are more or less taken for granted here.