The novel is set in the near future (2034-2060 AD), after the solar system has been surrounded by an impenetrable shield called the bubble. The bubble permits no light to enter the solar system and as a consequence the stars can no longer be seen.
The central premise of the novel is that the bubble has been constructed by aliens to prevent humanity from wreaking massive destruction on the rest of the universe. Disdaining the use of more ordinary threats, Greg Egan claims that the human brain is responsible for all causality, by collapsing wave functions representing systems into a particular eigenstate. Human observations of the universe were reducing its diversity and potentiality (for instance, by rendering it uninhabitable to beings that relied on stars being something other than the enormous nuclear fusion-powered furnaces human astronomers have observed them to be).
In the course of the novel, the situation is further complicated when human researchers discover a way of modifying the brain to provide conscious control over the process - allowing people to suspend wavefunction collapse at will, and to choose which state the wavefunction will collapse to.
Quarantine is also a novel by Jim Crace, which was shortlisted for the Booker Prize.