The light of ancient mistakes reaches Masaq' Hub, the orbital's Mind, contemplates what it witnessed during the war. The novel's elegiac tone is established from the first chapter.
Chapter 2: Winter Storm
Mahrai Ziller, a Chelgrian composer in exile on Masaq', is introduced. His music and his political history are both relevant: he fled a civil war that the Culture's intervention caused, and he has not forgiven.
Chapter 3: Infra Dawn
The Chelgrian emissary Quilan arrives on Masaq' to persuade Ziller to return home. His true mission and its nature are withheld from the reader, but the novel establishes early that something is wrong with him.
Chapter 4: Scorched Ground
Hub's perspective: an ancient Mind maintaining a habitat of billions, its relationship to the war's aftermath and to the light that is arriving. The Culture's Minds are shown here as genuinely different from humans in their experience of time and memory.
Chapter ?: Airsphere
Quilan visits an Airsphere, one of the Culture's stranger habitats: a gas giant atmosphere maintained as a living environment. The chapter is partly tourism, partly the slow revelation of what Quilan carries with him.
Chapter 5: A Very Attractive System
Ziller and Quilan meet for the first time. Their conversation is the novel's central relationship: two people on opposite sides of a catastrophe that neither caused and both survived, who cannot quite stop circling what happened.
Chapter 6: Resistance is Character-Forming
Hub observes Masaq' and its billions of residents going about their lives, indifferent to the war's light arriving. The scale of what the Culture is and what it costs to maintain it is rendered in miniature.
Chapter 7: Peer Group
Quilan's past is revealed more fully: the civil war, its causes, the role that Culture contact played in destabilising Chelgrian society. The case against the Culture is made through a character who has personal reasons to make it.
Chapter 8: The Retreat at Cadracet
A retreat into the past: Quilan's memories of his wife Worosei and the life they had before everything. The novel holds its emotional weight in these chapters.
Chapter ?: Dirigible
Ziller's symphony is near completion. Its subject is the Idiran War, seen from outside the Culture, and the act of composing it has required him to think carefully about what he believes about what happened.
Chapter ?: The Memory of Running
Hub's account of the war's dead: the Minds lost, the humans lost, the weight of it carried across eight hundred years. One of the novel's most direct statements about what memory is and what it costs.
Chapter 9: Pylon Country
Quilan moves toward his mission's completion. What he has been sent to do becomes clear, and the question the novel has been building toward - whether it will work, and whether it matters - comes into focus.
Chapter 10: The Seastacks of Youmier
The seastacks: Ziller and Quilan in conversation again, further along than before. The Chelgrian's hidden purpose is almost visible to the reader, though not yet to Ziller.
Chapter 11: Absence of Gravitas
Absence of gravitas: the Culture's particular lightness in the face of everything is shown as both genuine and maddening to those who have lost things it has never valued enough to protect.
Chapter 12: A Defeat of Echoes
The symphony's premiere approaches. Ziller's relationship to his own work and to the world he has made on Masaq' is examined in the days before the performance.
Chapter ?: Flight
Hub discovers what Quilan actually carries. The response it chooses and the reasoning behind that choice is the novel's most direct statement about what the Culture values and what it is willing to sacrifice.
Chapter 13: Some Ways of Dying
Some ways of dying: the Chelgrian afterlife, the Soulkeeper technology, Quilan's wife in whatever passes for the next world among his people. The novel's treatment of death and what follows it is more generous than the Culture's own secular materialism.
Chapter 14: Returning to Leave, Recalling Forgetting
The day of the concert. Ziller conducts his symphony about the war as the light of that war finally arrives. Quilan is in the audience. Hub has made its decision.
Chapter 15: A Certain Loss of Control
The loss of control: what happens at the concert, and what it costs, and what Hub chose to accept rather than prevent. The novel's climax is quiet in a way that makes it worse.