Shortly after the Earth's population topped 10 billion, computing technology began reaching the point where artificial intelligence could exceed that of humans through the use of closed timelike curves to send information to its past.

Messages left behind, both on computer networks and in monuments placed on the Earth and other planets of the inner Solar System carry a short statement from the apparent perpetrator of this event: "I am the Eschaton; I am not your God.I am descended from you, and exist in your future.Thou shalt not violate causality within my historic light cone.

"Earth collapses politically and economically in the wake of this population crash; the Internet Engineering Task Force eventually assumes the mantle of the United Nations, or at least its altruistic mission and charitable functions.

Some of the latter had regained the same, or higher, technological levels due in part to the "cornucopia machines", molecular assemblers that can recreate objects in predefined patterns or duplicate others, the Eschaton left them with.

At first they request food or other modest needs, but then Burya Rubenstein, exiled to the colony for his role in leading an uprising, asks for a cornucopia machine in return for a political tract on the disruptive effect a sudden singularity would have on repressive regimes.

Of greater concern to Rachel is that it may be planning to approach Rochard's World via a closed timelike loop, arriving there shortly after the Festival did, but earlier than the Navy left the capital.

She recruits Martin Springfield, an Earth-based engineer who has been hired by the New Republic's Admiralty to upgrade its drive systems, to keep an eye out for any signs of such a plan.

Late one night, while signing seemingly endless orders and communiqués, he is visited by Sister Stratagems the Seventh, a creature resembling a giant mole rat.

Sister Stratagems faults Rubenstein for the shortcomings of the revolution—it was foolish, she explains, for him to rely on revolutionary traditions in the midst of a singularity and its all-encompassing constant radical change.

As the Lord Vanek approaches battle, Vassily Muller, a young secret police agent assigned to the ship arranges to have Martin arrested as a spy.

Vassily and other crewmembers are sucked out into space when they attempt to break in afterwards; he alone survives, wearing emergency protective gear, and is eventually picked up by Rachel and Martin as they descend to Rochard's World, where they arrange, through the Critics, to meet Rubenstein.

Monitoring the battle from their own lifeboat, Martin and Rachel are unsurprised by the outcome, and explain to an angry Vassily how, despite its lack of intentions, the Festival's visit indeed represented an existential threat to the Republic since information wants to be free.

At Plotsk, where skyscrapers of stratospheric height have been erected, Rubenstein and Sister Stratagems meet some of his former comrades, many of them now cyborgs, and realises that the revolution he started has now grown beyond needing him or any other leader.

They find the governor, who had been granted his wish to once again become a young boy with faithful animal companions, mummified on a hillside where the Festival saved him from zombification at the hand of the Mimes, another associated species, with an X-ray laser blast that left his body exposed to dangerous levels of ionizing radiation.

Vassily appears and attempts to kill Rubenstein, identifying himself as his son, but Rachel stops him with a stun gun although he irreversibly damages the cornucopia machine in the process.

The arrival of the cornucopia machines and the cybernetic enhancements made available by the Festival force not only the collapse of the existing social, economic and political orders but prevent their replacement by Rubenstein's revolution.

[6] "People suddenly gifted with infinite wealth and knowledge rapidly learned that they didn't need a government—and this was true as much for members of the underground as for the workers and peasants they strove to mobilize.

He needed to have faster-than-light travel between those worlds, but that also created the problem of avoiding causality violations, one of the many limitations of the singularity for space opera that he credits Vernor Vinge, who wrote an important early essay on the concept, for having highlighted in his novel A Fire Upon the Deep.

"[8] To satirise these failings of the subgenre, he chose "the most barkingly insane naval expedition of recent history" as a model: the Russian Baltic Fleet's 18,000-mile (29,000 km) journey around Africa and Asia in an attempt to retake Port Arthur in China during the Russo–Japanese War in 1905, with sailors who were largely new recruits and mostly new ships on their shakedown cruise.

Add the fleeting twilight nights (we get maybe 4 hours of complete full dark at that time of year) and the pervasive random weirdness—you can go shopping dressed as a Dalek or a 17th-century French aristocrat and nobody will blink at you—and it seemed like the perfect metaphor for what the New Republican Navy was going up against.With that element in place, Stross cut a large chunk of what he had already written and wrote the novel's opening sequence.

Veronica Hollinger of Trent University sees it as an example of what has been called New Baroque Space Opera, along with Iain Banks' Consider Phlebas and Alastair Reynolds' Redemption Ark.

"[They] are contributing to a self-conscious revival, in new directions, of one of SF's oldest (and most denigrated) subgenres, constructing futures that—quite cheerfully, for the most part—reflect back to us the incredible complexity of the technoscientific present.

"[20] Markus Öhman, an undergraduate education student at Luleå University of Technology in Sweden, has looked at how the novel deals with class and gender issues as they intersect the singularity.

[22] The Critics' class-and-gender hierarchy is mirrored by the New Republic, which oppresses women so thoroughly, Öhman observes, that only one female of that society has even a brief real speaking role in the book,(and she is an atypical one at that—the revolutionary confronting Mr. Rabbit).

"[23] So, too, with social class: "... [F]or the duration of the Festival's orbital presence, Rochard's World is a classless anarchistic non-society with small zones of stability filled with modified humans.

During the staged court-martial she appears ready to become another example of a self-empowered woman who voluntarily renounces all or some of her power to save the man she loves, but instead she subverts the trope, drawing on her implants to appropriate the role of a male action hero and rescue Martin.

[11] It follows Martin and Rachel, now in a long-term relationship, as they try to avert a potentially devastating revenge attack by the remnants of a colony destroyed by an induced supernova, and uncovering a more serious threat in the process.

As a result of the economic upheavals, the remaining navy crews would be long in arrears on their pay, likely to mutiny and desert for more lucrative opportunities in piracy, using their military skills to violently rob starships of valuable cargo.

This would have brought them into conflict with the predominant pirates, who prefer the more discreet technique of auditing the cargo and work with commodities traders to make money through arbitrage on the destination planet.

[9] Singularity Sky has been cited outside the science fiction audience by writers trying to explain to readers the title concept, or at least the effects of the rapid change the novel depicts in a real-world context.