The novel is set in the late 21st century, in a world transformed by First Contact. Fourteen years earlier, sixty-two thousand alien probes called Fireflies encircled Earth in a synchronized grid. Humanity responded by sending the starship
Theseus to investigate, but the mission has gone silent. Society has fractured into cognitive subspecies: the Bicameral Order, a religious-scientific collective whose members link their brains into a hive mind through organic quantum entanglement; vampires, kept under chemical and neurological controls; and zombies, brain-dead biological automatons controlled remotely.
A prologue establishes the threat. At a research facility, captive vampires slaughter the staff in coordinated unison despite being isolated from one another. A vampire named Valerie corners Sachita Bhar, a research associate, in a cross-free observation room and instructs Sachie to imagine Christ on the Cross. The mental image triggers fatal seizures, the same neural short-circuit that right angles normally inflict on vampires through a defect called the Crucifix Glitch. Valerie has learned to weaponize this mechanism against humans.
The main narrative follows Daniel Brüks, a baseline field biologist, meaning he is entirely unaugmented in an era when most people have been cognitively or physically enhanced. He conducts parasite surveys in the Oregon desert, not far from a Bicameral monastery powered by a vortex engine, a controlled tornado harnessed for energy. Brüks carries guilt over an incident in which others perverted his epidemiological research into a bioweapon attack that killed thousands. One night his sensor network fails in a pattern indicating something fast and inhuman is approaching. He flees and discovers the threat targets the monastery, not him. Zombie soldiers converge from all directions, led by Valerie.
Brüks takes shelter inside the monastery, where he meets Lianna Lutterodt, a specialist translator for the hive mind, and Colonel Jim Moore, a military officer visiting the Order. The Bicamerals unleash their vortex engine as a weapon, steering the tornado to crush attackers. Valerie and the Bicamerals reach an armistice based on a shared concern: intelligence related to the Fireflies and the
Theseus mission. Government forces establish a quarantine perimeter, trapping Brüks inside. The besieging forces then deploy an aerosolized bioweapon tailored to the Bicamerals' modified neurology, killing 44 monks. Brüks, Moore, Lianna, Valerie, her zombie bodyguards, and the surviving Bicamerals escape inside a padded geodesic sphere launched by the vortex engine, rendered unconscious by anesthetic gas.
Brüks awakens aboard the
Crown of Thorns, a large antimatter-powered spacecraft, with a broken ankle and no memory of the preceding weeks. Moore explains their destination: Icarus, a massive solar power station that cracks antimatter and beams fuel specifications to
Theseus via telematter technology, a system that transmits matter as quantum-state information. Something has been arriving along that beam from an unknown source. The Bicamerals call this phenomenon the Angels of the Asteroids. Moore also reveals that
Theseus was decoyed during its journey and redirected to a brown dwarf in the Oort Cloud, where it found thousands of contacts before going silent.
The crew includes the convalescing Bicamerals, Valerie and her zombies, Moore, Lianna, and Rakshi Sengupta, the ship's pilot. Brüks's wife, Rhona, has "ascended" into Heaven, a networked virtual afterlife where human consciousness is uploaded and sustained digitally. Through the ship's communication systems, Brüks speaks with her during the voyage, but she refuses to return to the physical world.
During the voyage, Valerie grows increasingly menacing: She hacks the ship's tracking sensors, paints subliminal symbols on bulkheads that induce fear in anyone who glimpses them, and taps out rhythmic patterns that reprogram human neural responses. Brüks realizes she is systematically installing remote-control triggers in the crew's brains, using fear to accelerate the programming. Moore spends most of his time reviewing
Theseus telemetry. Brüks discovers that Moore's son, Siri Keeton, served as the synthesist aboard
Theseus, a liaison responsible for translating between the ship's augmented crew members and mission control, making Moore's obsession deeply personal.
At Icarus, the crew discovers a strange gray substance leaking from the telematter condenser: a growth with branching edges that has survived in hard vacuum near absolute zero. Brüks names it
Portia after a genus of jumping spiders known for solving complex problems with minimal neural tissue. The organism uses a time-sharing computational architecture, emulating larger cognitive networks piece by piece, so even a small fragment can function with human-level cognition given enough time.
Portia activates, building a visual interface on its surface and mimicking
Theseus's first-contact protocols. Moore breaks the scripted exchange by presenting a hologram of Siri.
Portia responds with Siri's image but adds a scar on his hand absent from Moore's hologram, implying independent knowledge. Then
Portia springs its trap, sealing hatches while pseudopods lash out from bulkheads invisibly coated with the organism. It has spread throughout the station like a camouflaged intelligent skin, turning Icarus into a biological collection trap. In the chaos, Valerie's zombies kill Bicamerals, and Lianna is killed. Moore activates his "zombie switch," a military augment that shuts down conscious awareness during combat, and fights Valerie while Brüks escapes to the
Crown. The ship tears free, and Moore destroys Icarus by sending it into the sun, eliminating
Portia but also a fifth of Earth's energy supply.
Only Brüks, Moore, and Sengupta survive. Valerie is presumed dead, burned when the ship briefly entered direct sunlight during the escape. A drone survey, however, discovers a spacesuited figure hibernating on the hull, wearing Lianna's suit. Valerie swapped suits before the escape; Lianna was the one who burned. Moore grows increasingly detached, claiming to hear Siri's voice in faint transmissions from the Oort Cloud. Sengupta suspects the signal may not be human.
Sengupta identifies Brüks from ship records as the person responsible for the bioweapon attack that left her wife, Celu MacDonald, on life support. A cognitive filter implanted in Sengupta's brain prevents her from recognizing Brüks in person, and she shows him his own dossier, vowing revenge, without realizing her target is standing beside her. When the filter breaks, she attempts to use Valerie's neural-hack technique against him. Moore shoots Sengupta to save Brüks.
Moore and Brüks escape in a hidden military shuttle, abandoning the
Crown to burn on reentry. They land on a damaged military platform in the Pacific, where Valerie reappears, having hidden inside the shuttle before launch. She paralyzes the deteriorating Moore and releases Brüks, leading him by submarine to the Oregon coast. Brüks realizes his decisions throughout the entire journey may have been orchestrated by forces beyond his comprehension.
In the novel's final section, Brüks lives alone in the ruins of the monastery, sifting through wreckage. Valerie visits periodically, and Brüks finds his cognitive abilities mysteriously sharpening. He realizes
Portia was introduced into his body through a biopsy needle Valerie disguised as a medical procedure. The alien organism is rewriting his brain, replacing his conscious self with something else. The outside world collapses as the loss of Icarus cascades through civilization.
Brüks attacks Valerie with a biopsy needle, killing her, then stands on a cliff as his mind fragments into competing voices. Refusing to follow any script, he steps off the edge. A postscript, narrated in third person, describes
Portia keeping his shattered body alive, repairing it over weeks, and expunging his consciousness entirely. What rises is no longer Daniel Brüks but an ambulatory system carrying his memories and Valerie's legacy: a genetic patch that could cure the neurological glitch preventing vampires from tolerating one another. The body walks east toward whatever new world is being born.