Aboard the lighthugger Nostalgia for Infinity, year 2543, Triumvir Ilia Volyova, one of three senior crew officers, rides an internal elevator down the ship’s four-kilometer central shaft. The ship is vast and partially decayed. Volyova visits the cryogenically frozen Captain Brannigan, who is infected with the Melding Plague, a technological disease that causes machinery and organic matter to fuse grotesquely. His reefersleep casket is cracking from the growth spreading from his body. Volyova scrapes samples and briefly warms his brain to speak with her.

The Captain communicates via machines that translate his brain activity. He asks whether they are traveling to find Dan Sylveste on Yellowstone. Volyova confirms this is Triumvir Sajaki’s plan. The captain recalls that Sylveste did not come willingly before. Volyova confesses she had been training a gunnery officer named Boris Nagorny to interface with the ship’s cache of powerful weapons via neural implants, even though he suffers from a range of intense mental health episodes. The captain advises her to kill Nagorny and to hide the body inside a failed reefersleep unit to make his death appear accidental. She follows this advice and, as the ship approaches Yellowstone, she reflects on what she should do next. Nagorny suffered nightmares involving an entity called Sun Stealer. He attacked Volyova and pushed her into an elevator shaft. Volyova survived by reversing the ship’s thrust, which killed Nagorny. She removed the molecular implants from his severed head, thinking of his replacement.

On Resurgam, Sylveste invites Sluka to leave while he and anyone wishing to remain will continue to work the dig. He accuses Sluka of being “a dissenter” (24), working for Girardeau to spread discord. Sluka challenges his belief that the Amarantin caused the Event but she and her followers agree to leave behind one of the crawlers so that Sylveste, Pascale, and a few loyalists can stay behind to uncover the obelisk. After Sluka’s departure, the storm passes as the remaining workers uncover the obelisk’s map. Syleste is determined that they should uncover the truth about what the Amarantin did to cause the Event, so that humanity does not make the same mistake. An arriving ship brings news that the other crawler crashed, killing everyone onboard. Sylveste is then arrested.

On Yellowstone (a human colony in the Epsilon Eridani system) in the year 2524, Ana Khouri, an ex-soldier working as a contract assassin for a Shadowplay company run by a Hermetic named K. C. Ng, tracks and shoots her target through Chasm City, the once-prosperous but now malformed human habitation. As she travels through the city, she thinks about her fractured memories and her estranged husband. She was separated from him by a clerical error which sent her on a journey into deep space; by the time the error was noticed, years had passed. She was hired by an assassination corporation, which hunts rich people to distract them from their sense of ennui. Her target is a wealthy man named Taraschi; she kills him with a slow-acting toxin dart. Taraschi reveals that he arranged the contract himself; he wanted to die so that he could have his mind scanned into a computer and join his deceased mother, Nadine Weng-da Silva Taraschi, one of the original Eighty whose brains were uploaded into the computer systems. After his family escorts him away, a stranger named Carlos Manoukhian appears and holds Khouri at gunpoint. He informs her that she now works for someone called the Mademoiselle.

In the year 2561, 10 years after his arrest, Sylveste is imprisoned in Cuvier (now Resurgam City). The colony is controlled by Girardieau, who deposed Sylveste in a coup. Sylveste watches a street protest as Girardieau’s militia mobilizes against demonstrators. Girardieau suggests that a biography of Sylveste should be written, one which tells the story of Sylveste’s father and his role among the Eighty. Sylveste cooperates with the biography under duress, having been promised access to field data about the obelisk. Pascale Dubois visits Sylveste, having been appointed to work on the biography. Sylveste knows that Girardieau hopes to discredit him. Pascale presses Sylveste about what happened to Calvin’s alpha-level recording, the fully conscious digital copy made during the Eighty, a controversial experiment in which Calvin and 79 volunteers were destructively brain-scanned. Pascale argues the alpha recording disappeared suspiciously around the time Sylveste visited the Shrouders (alien structures whose surfaces kill most who approach them).

Aboard the Nostalgia for Infinity, Volyova is warned by a janitor-rat, a biochemically modified rodent that functions as a ship sensor, that the rest of the crew has awakened from reefersleep. She finds Yuuji Sajaki and Abdul Hegazi. They are, together with herself, the Triumvirate, the ship's real center of power. Below the Triumvirate there are two more crew of equal rank. Their names are Kjarval and Sudjic; they are biotically modified chimerics, having been fitted with animal-like medications. They are also Ultras, a group that grows dreadlocks to signify the number of times that they have been through reefersleep. Sudjic was close to Nagorny, so Volyova must feign ignorance about his fate. Visiting his cabin with Hegazi, she examines the coffin Nagorny made for himself in the depths of his episode. It is inscribed with warnings about the Sun Stealer.

Meanwhile, Khouri is escorted to a meeting with the Mademoiselle by Manoukhian. He takes her far above the streets, into a lavishly decorated space that looks down on Chasm City. There, the Mademoiselle reveals herself as a Hermetic and tells Khouri that she is being hired to assassinate someone against their will. Khouri has been chosen, she says, because the clerical error which separated her from her husband, Fazil, has made her disillusioned about society. Khouri is being sent to Resurgam where, Mademoiselle says, a man called Sylveste has just arrived.

In 2546, the Nostalgia for Infinity arrives in the Epsilon Eridani system. Volyova and Triumvir Hegazi, her heavily augmented chimeric crew officer, dock at Carousel New Brazilia, an orbiting habitat. After passing customs, they travel by rickshaw through Rimtown. Volyova explains her plan to find a new gunnery officer recruit, seeking someone with hidden military experience. She and Hegazi drink at the Juggler and the Shrouder, an Ultra (interstellar spacefarer culture) bar. Triumvir Sajaki arrives in Komuso disguise and reports that Dan Sylveste left the Yellowstone system approximately 50 years before and is now on a planet called Resurgam. The crew must change course.

Sylveste reviews the story of his life, as written by Pascale. The biography is interactive, allowing him to feel as though he is stepping inside a nonlinear recreation of his memories. A young Sylveste regularly visits Philip Lascaille, a former scientist who approached one of several alien structures known as Shrouds. Unlike many who previously approached a Shroud, Lascaille survives, but returns with most of his mind scrabbled. Sylveste visits him regularly, hoping that Lascaille’s nonsensical attempts to communicate may contain useful information. One day, Lascaille speaks lucidly, explaining that the Shrouders were alien beings who once encountered the Pattern Jugglers, world-sized oceanic organisms that store and imprint consciousness patterns. Swimming in a Juggler ocean and presenting the right mental diagram could cause the Jugglers to imprint a Shrouder neural pattern onto a human brain, allowing passage through the Shroud’s deadly defenses. He warns that the Shrouds protect vast and dangerous technologies. Shortly afterward, Lascaille drowns himself. Together with a woman named Lefevre, Sylveste visits a Juggler planet and imprints the Shrouder consciousness on his mind. He and Lefevre visit a Shroud. Lefevre and the crew are killed; their ship is nearly destroyed. Sylveste continues deeper into the Shroud boundary, called Revelation Space. Sylveste survives, spends weeks repairing the lighthugger alone, and gradually realizes during sleep that something inside the Shroud communicated with him, though the message is too alien to translate.

Khouri wakes in the Mademoiselle’s Château des Corbeaux in Chasm City, 22 years after their first meeting. Manoukhian informs her of the elapsed time. The Mademoiselle, speaking from a palanquin, tells Khouri she has located a crew traveling to Resurgam and wants her to assassinate a man named Sylveste. She reveals that she possesses Fazil, still in a reefersleep casket. The Mademoiselle has orchestrated everything in Khouri’s life to prepare her for the mission.

In 2546 on Carousel New Brazilia, Volyova waits at the Juggler and the Shrouder to interview a recruit. Ana Khouri arrives, presenting herself as someone seeking passage, apparently believing the ship is heading to Sky’s Edge, her home colony where she fought in a war alongside her husband before the apparent error which sent her into reefersleep. Volyova does not correct this and agrees to take Khouri aboard.

Inside Khouri’s mind, the Mademoiselle’s implant, a beta-level simulation inserted while she slept, coaches Khouri silently. The implant confirms Volyova’s ship is indeed heading to Resurgam. She reveals she placed Fazil in reefersleep as leverage and that she has also inserted protections into Khouri’s mind which will counteract any technology which tries to force Khouri to become loyal to Volyova. Angry with the Mademoiselle for deceiving her, Khouri has no choice but to continue in her deceit.

Calvin’s simulation, which has accessed Pascale’s compad files without her knowledge, reveals to Sylveste that Pascale’s real surname is Girardieau: She is Nils Girardieau’s daughter, working under a false name. In exchange for offering up access to Calvin’s beta-level simulation—which contains information and memories that Sylveste knows will be used to ruin his reputation—Girardieau agrees to perform tests on the obelisk. These findings confirm the creation of the obelisk to a time near (or sometime after) the Event. Girardieau eventually reveals to Sylveste that many similar obelisks were found. In the aftermath of the coup, Girardieau has restarted much of the archeological research into the Amarantin. He takes Sylveste to find what has been uncovered near the obelisks. Buried deep beneath the ground, there is a giant unblemished sphere. Girardieau takes Sylveste inside and shows him the alien city which is hidden within.

Three weeks after leaving Yellowstone, Volyova has administered loyalty-altering therapies to Khouri, biochemical treatments designed to bind her to the crew. Khouri’s skull now bears scars from procedures to implant the gunnery interface hardware previously removed from Nagorny’s head. Volyova takes Khouri to the spider-room, a glass-walled observation pod that extends outside the ship’s hull on articulated legs. Volyova presents the room as a place to hear ghost voices: time-dilated radio transmissions from other lighthuggers, whose crew voices are slowed and mournful due to relativistic time dilation. Khouri correctly identifies the phenomenon. Volyova then asks Khouri whether the phrase “Sun Stealer” means anything to her. Khouri says no, though notes Volyova’s use of the word “yet.” Volyova then escorts Khouri to the cache chamber, showing her 40 hell-class weapons. These are massive and inscrutable devices capable of destroying planets or destabilizing stars. Volyova states that she has successfully tested a small number in combat. When she places Khouri in the gunnery chair, Khouri feels immediately familiar. In her head, the Mademoiselle begins to have doubts.

On Resurgam, Sylveste and Pascale, now working together on the inscriptions of the buried Amarantin city via a data simulation, study the central temple spire and outer walls. The wall fresco shows Amarantin performing various functions; None of the Amarantin have wings, consistent with their creation myth. The Birdmaker god, the myth tells, granted sentience in exchange for their wings but forbade them from flying again. However, the spire bears a statue of a winged Amarantin figure, which violates the prohibition. The accompanying text references the Banished Ones, a faction that rejected the Birdmaker agreement. Their leader bears a name that translates, tentatively, as Sun Stealer.