Quarantine (Egan novel)
A hard SF novel fusing quantum mechanics with a detective plot.
Greg Egan’s 1992 hard science fiction novel *Quarantine* wraps a detective story around a deep dive into the Copenhagen interpretation of quantum mechanics—specifically the idea that consciousness triggers wave function collapse. Egan admitted he picked this version more because it made for a good story than because he thought it was true.
The action takes place between 2034 and 2080. An impenetrable barrier called the Bubble has sealed off the Solar System, presumably built by aliens for unknown reasons. No starlight gets through, sparking mass panic, claustrophobia, and terrorism. People commonly use neural mods—engineered microorganisms that carve programmed pathways in the brain—to implant skills, emotions, or altered states, and illegally to force thoughts.
The narrator, Nick, is a former cop turned private eye. He carries tactical mods that suppress emotion and boost analytical thinking. After his wife died, the trauma triggered his emotional suppression mod, and he later bought a mod that simulates the feeling of her still being alive, neatly solving his grief.
Nick takes a case involving Laura, a woman who keeps vanishing from a psychiatric institute. Staff say she couldn’t have escaped without walking through walls, but this time she was kidnapped. Following leads to New Hong Kong, Nick finds the group behind it, the Ensemble, but gets captured. They implant him with an illegal Loyalty Mod, making him genuinely believe in their cause. He ends up guarding their project: a new mod perfected by studying Laura. Called the Eigenstate Mod, it lets the brain consciously control wave function collapse. Researcher Po-kwai suspects the Bubble exists because humanity’s aggressive collapsing of wave functions may have harmed alien civilizations that lacked that ability.
When using the mod, a user becomes “Smeared”—existing in a superposition of states where every possible action is equally real. Once one version succeeds, they deactivate the mod, collapsing all possibilities into that one reality. This lets the user control probability, but raises moral questions: Nick sees deactivating the mod as murdering all the other equally real versions of himself.
Nick meets a subgroup of Ensemble members also controlled by the Loyalty Mod. They call themselves the Canon and argue that since the mod only demands loyalty to “the Ensemble” without defining it, they—as
- author
- Greg Egan
- published
- 1992
- genre
- Hard science fiction, detective fiction
- setting
- Near future (2034–2080)
- key_concept
- Eigenstate Mod allowing conscious control of wave function collapse
Lore & Background
The novel is set after an impenetrable shield called the Bubble surrounds the Solar System, blocking all starlight and causing societal panic. Neural mods are commonplace, and the narrator Nick, a private eye, uses tactical mods to suppress emotions. He investigates a woman named Laura who vanishes from a psychiatric institute, leading him to the Ensemble group, which implants him with a Loyalty Mod. The Ensemble has perfected the Eigenstate Mod, which allows the brain to consciously control wave function collapse, enabling the user to exist in a superposition of states and seemingly control probability.
Reader's Guide
Quarantine is significant for its ambitious integration of quantum mechanics into a narrative that questions reality, identity, and morality. The novel's use of the consciousness-causes-collapse interpretation, though acknowledged as chosen for entertainment, allows Egan to explore philosophical dilemmas about the nature of existence and the consequences of controlling probability. Critical reception noted its fast pace and imaginative scope, though some reviewers found its metaphysical explanations demanding and its structure flawed. The novel has been translated into multiple languages and remains a notable example of hard science fiction that challenges traditional humanism.
Did You Know?
- The novel's Bubble is an impenetrable shield that blocks all light from entering the Solar System.
- The Eigenstate Mod allows users to exist in a superposition of states, making every possible action equally real.
- The narrator Nick uses a mod that simulates the feeling of his deceased wife still being alive.
- The novel was translated into German in 1993 and into at least ten other languages by 2006.
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