[5] The story follows a crew of astronauts sent to investigate a trans-Neptunian comet dubbed "Burns-Caulfield" that has been found to be transmitting an unidentified radio signal, followed by their subsequent first contact.

In the year 2082, tens of thousands of coordinated comet-like objects of an unknown origin, dubbed "Fireflies", burn up in the Earth's atmosphere in a precise grid, while momentarily broadcasting across an immense portion of the electromagnetic spectrum, catching humanity off guard and alerting it to an undeniable extraterrestrial presence.

While the crew is in hibernation en route, the just-arrived second wave of probes commence a compounded radar scan of the subsurface of Burns-Caulfield, but this immediately causes the object to self-destruct.

Theseus is re-routed mid-flight to the new-found destination of the signal: a previously undetected sub-brown dwarf deep in the Oort cloud, dubbed 'Big Ben'.

Theseus probes Rorschach and finds it to have hollow sections, some with atmosphere, all filled with levels of radiation that render remote operation of machinery virtually impossible and would kill a human in a matter of hours.

Despite this and over Rorschach's objections the whole crew except the mission commander enters and explores in a series of short forays, using the ship's advanced medical facilities to recover from the damage the radiation inflicts on their bodies.

They theorize that humanity could be an unusual offshoot of evolution, wasting bodily and economic resources on the self-aware ego which has little value in terms of Darwinian fitness.

Open warfare breaks out between the humans and the Scramblers and Theseus eventually decides to sacrifice itself and its crew using its antimatter payload to eliminate Rorschach.

As he travels back towards the inner Solar System, he hears radio broadcasts which suggest that the vampires have revolted and may be exterminating baseline humanity.

[10][11] Relevant to these questions is a plot element near the climax of the story, in which the vampire captain is revealed to have been controlled by the ship's artificial intelligence for the entirety of the novel.

[7][10][11][12] That is, consciousness may have been naturally selected as a solution for the challenges of a specific place in space and time, but will become a limitation as conditions change or competing intelligences are encountered.

[12] Enhanced pattern-matching skills comparable to some forms of autism combine with this "hyperthreading" to make them invaluable in developing unusual and often very effective approaches to solving complex problems.

Carl Hayes, in his review for Booklist, wrote: "Watts packs in enough tantalizing ideas for a score of novels while spinning new twists on every cutting-edge motif from virtual reality to extraterrestrial biology.

"[16] Jackie Cassida in her review for Library Journal wrote: "Watts continues to challenge readers with his imaginative plots and superb storytelling.

Watts is one of the crown princes of science fiction's most difficult subgenre: his work is rigorous, unsentimental, and full of the sort of brilliant little moments of synthesis that make a nerd's brain light up like a pinball machine.