The Prefect

The novel begins with Dreyfus being sent out on a routine assignment to lock down a glitter-band habitat for polling violations. His superiors send one of his deputies, Thalia Ng, to distribute software upgrades around the Glitter Band to prevent anyone from attempting a similar violation.

In the meantime, Dreyfus is sent to investigate the recent destruction of a habitat named Ruskin-Sartorious. Analysis indicates that the habitat has been destroyed by the flame of a Conjoiner Drive, and Dreyfus's team believe the lighthugger Accompaniment of Shadows, the only one to have been near the habitat in recent weeks, is responsible. Before they can conclude their investigation, however, the Ultranauts take justice into their own hands and destroy the ship, but not before Dreyfus is able to converse with the captain, who convinces him that his crew were not responsible. Believing him to be truthful, Dreyfus and his deputy, the hyperpig Sparver, decide to investigate the matter further.

Dreyfus and Sparver interview digital backups of the inhabitants of Ruskin-Sartorious. Dreyfus speaks with one of them about the Clockmaker, an alien machine which formerly lived in a Glitter Band research centre, creating, as its name suggests, clocks, before it began a violent killing spree and was destroyed with nuclear weapons nine years prior to the novel. He and Sparver then analyse communication records from the Ruskin-Sartorious habitat, and discover links with an orbiting asteroid owned by the Nerval-Lermontov family (a member of which was called Aurora). They defeat its defence systems and penetrate inside, discovering a Conjoiner starship trapped inside. One of them, Clepsydra, has escaped and is hiding. She meets with Dreyfus and tells him that she and the other Conjoiners had been enslaved by Aurora (now an extremely powerful software entity) to use the Exordium to predict the future. The Conjoiners predict a future devastated by what is implied to be the Melding Plague, and Aurora has been planning to respond to stop it (use of the Exordium creates a new timeline which can be changed to avoid the future the Exordium describes). She and Dreyfus escape as a ship under Aurora's control arrives and destroys the habitat.

At the same time, Thalia has distributed the software upgrade to the required four habitats across the Glitter Band, but it appears to be malfunctioning; information access is shut down in the habitats she has visited, and servitors (service robots used across the Glitter Band) are rounding up and exterminating civilians. She and some of the survivors of the last habitat take refuge in its polling core tower, barricading the entrance. Outside, the servitors begin to construct "weevil" war machines using plans stolen by Gaffney, a Senior Prefect secretly in alliance with Aurora.

Back at Panoply, with Dreyfus in the field and out of communication, Gaffney manipulates the Senior Prefects into voting Aumonier out of office. Clepsydra is taken into isolation, whilst Dreyfus explains the situation to the Senior Prefects. Unbeknownst to him, however, Gaffney kills Clepsydra and frames Dreyfus. The Prefects debate what to do about the emergence of the weevils, which have now left the four original habitats and are moving towards others.

Before very long, however, Gaffney is exposed as the murderer of Clepsydra when attempting to interrogate Dreyfus. He admits to his role in the weevil outbreak and informs the Prefects that Aurora is responsible. Aurora herself contacts Panoply and demands that they stand down, claiming to be taking over the Glitter Band for its own good. Aumonier, now back in power, refuses and orders Panoply to ready for war. Although Thalia escapes from Aurora's forces during a disastrous attack by Panoply, simulations run by the Prefects indicate that they have virtually no chance of success; the weevils are destroying habitats and converting them into even more weevils, grossly outnumbering the Prefects.

Aumonier speaks to Dreyfus and tells him that the aforementioned Clockmaker was not actually destroyed nine years previously; part of it survived and was recovered by Panoply. The ultra-secret Panoply unit, Firebrand, was established to research it. Although Aumonier ordered it shut down, she now believes its members relocated the Clockmaker to Ruskin-Sartorious. As the Clockmaker was the only intelligence in the Glitter Band capable of defeating Aurora, she attempted to destroy it. Dreyfus confronts members of Firebrand, who confirm Aumonier's theory, but reveal that the Clockmaker was not in fact destroyed; Firebrand became aware of the attack in advance and moved the Clockmaker. Following them to the surface of Yellowstone, he and Sparver fight their way into an abandoned Amerikano colony, where the Clockmaker is being hidden. Sparver leaves to fight Gaffney, who is approaching the colony with bombs to destroy the Clockmaker.

Dreyfus meets with the Clockmaker, who reveals that he is actually Philip Lascaille, a character in Revelation Space who was believed to have committed suicide after meeting with the Shrouders, but was in fact scanned to produce a simulation, which was sent back to the Shrouders, who turned it into the Clockmaker. Dreyfus tells the Clockmaker what is happening. It incapacitates him and leaves. Regaining consciousness, Dreyfus meets with Sparver. They return to Panoply to find that the weevil attack has collapsed; the Clockmaker has uploaded itself into the Glitter Band's data network and is fighting a digital war with Aurora. As such, she is unable to control the weevils effectively, and the Prefects are destroying them in alliance with the Ultras. Dreyfus begins preparing to investigate the death of Philip Lascaille, having promised the Clockmaker he would bring those responsible to justice.

On 25 July 2017 Alastair Reynolds announced on his blog that his next book Elysium Fire would be a direct sequel to The Prefect which itself would be given the new title Aurora Rising, the better to fit with the Panoply stories being a series in their own right within the Revelation Space universe.[2]

• Revelation Space universe