Aboard the Lightfoot, Kern reflects on her inability to feel emotion, a deficiency she has become acutely aware of after briefly linking with Meshner’s neural implant. She quietly manipulates her crew to investigate the mysterious human signal from the second planet. Meanwhile, Meshner and Fabian continue their experiments in sharing consciousness. Meshner successfully experiences a Portiid “Understanding”—an inherited memory—of a failed courtship, but the process leaves him physically ill and experiencing synesthesia. The crew’s leaders, the Portiids Viola and Zaine, argue over the nature of the signal, which presents itself as a natural history of an alien world authored by someone named Erma Lante. Zaine believes it is a fiction, while Viola is convinced it contains invaluable scientific data. Kern secretly communicates with Meshner through his implant, stoking his interest while observing Viola’s ambition.

Helena and Portia remain prisoners, surviving on a fishy paste. Helena examines the archive and learns how Senkovi engineered the octopuses and lived out his life in orbit, believing he was the last human. The recordings document his lonely, decades-long effort to communicate with his creations. Helena realizes she possesses an advantage Senkovi lacked: knowledge of the octopuses’ current two-channel communication system. She reconfigures her translation software to decode their visual language, which means she can no longer translate for Portia. This highlights for Helena the persistent communicative gap between their species. Studying the archives, Helena finds a key recording where an octopus responds to Senkovi’s happiness, revealing a capacity for empathy. Feeling prepared, she uses her modified slate to initiate formal communication with her captors.

Fabian grows frustrated that the mission is disrupting his research with Meshner, whose health is deteriorating from their experiments. Fabian transmits a simple maze “Understanding” into Meshner’s implant. Meshner experiences the maze not as a simple test but as a deeply unsettling, realistic simulation of a sunken ruin. His implant is running at maximum capacity, commandeering computational resources from the ship and his own brain. 

The Lightfoot arrives at the signal’s source: a derelict Old Empire terraforming station, which has been heavily modified with octopus technology and shows signs of a recent battle. Viola insists they board to retrieve what she believes is data on a new form of alien inherited memory. Kern’s attempt to connect with the station fails; the signal has ceased, and no active network remains. She sends drones inside, which follow power conduits to a sealed chamber just as Zaine reports that octopus warships are approaching their position.

The automaton Artifabian is sent to the derelict station to open the sealed interior door. It operates an airlock and enters a small, air-filled chamber containing an antique human environment suit and a large console clearly built by aliens for human use. The door has no internal handle, revealing the room is a prison. Kern determines the console is the signal’s source but can only be operated efficiently by human hands. Zaine, already in her suit, volunteers to go aboard. Kern insists Meshner accompany her for safety. Meshner is terrified but finds himself overwhelmed by a strange excitement (actually Kern’s influence over his neural implant) that compels him to agree. He tries to warn Fabian that his implant is malfunctioning, but without Artifabian to translate, his warning goes unheard.

On the station, Meshner feels controlled by the powerful, artificial excitement as he and Zaine enter the prison chamber. Kern directs Meshner to the console. As he interacts with it, his implant generates a virtual space where he meets an avatar of Kern. She is frustrated, having found only an incomplete data archive and no sign of the intelligence that was broadcasting it. Their investigation is interrupted by a signal from the Lightfoot: Helena and Portia are alive and have made contact. As this news arrives, the antique environment suit from the chair stands up behind Zaine, revealing itself as an animate, boneless entity. It attacks. Artifabian intervenes, tearing the suit’s leg and releasing a dark, oily fluid that fragments into multiple, smaller living organisms. The organisms crawl up Meshner’s suit and manipulate his helmet’s release catch. Kern’s voice enters his mind, stripping away his fear and giving him cold clarity. To save Zaine, Meshner orders Artifabian into the airlock and has it seal the inner door, trapping him inside as the creature opens his faceplate.

The narrative shifts to the perspective of the Nodan parasite. The organism recalls waking and slowly remembering its existence. It had assimilated the human scientist Erma Lante, experiencing the universe through her senses for a long time. It was eventually forced into a dormant state, leaving only a looping recording of Lante’s scientific observations broadcasting from the station. The arrival of the Lightfoot crew has awakened it, and it is now ready to begin a new “adventure.”

Helena and Portia lose contact with the Lightfoot. From their captors’ communications, they learn the octopuses are terrified of a contagious organism from the planet Nod, the same one described in ancient recordings made by a human named Baltiel. While most octopuses are hostile, Helena observes covert signals suggesting some are more open to contact. Portia then discovers a countdown in the data stream, revealing that an octopus warship has been stalking the Lightfoot and is about to launch a preemptive attack. The captors allow them to send a warning, but the decision to attack was made long before. Kern’s final, fragmented transmission confirms incoming missiles and her desperate attempt to re-establish contact with the now-infected Meshner. Data from an octopus source later shows the Lightfoot being struck and sent spiraling into the planet’s atmosphere.

The narrative shifts to the past. 

Senkovi, now 189 years old, lives alone aboard his station, the Aegean, orbiting the water planet Damascus. He has watched his creations develop a civilization but has never been able to fully understand them emotionally. He is haunted by the deaths of the people on Nod, particularly Baltiel. Senkovi believes the Nodan organism survived the crash of Baltiel’s shuttle and lies dormant in the wreckage at the bottom of Damascus’s ocean. To protect his creations, he establishes a powerful, species-wide taboo forbidding any octopus from ever approaching the crash site. Senkovi eventually dies in his aquatic habitat, leaving his creations to their fate.

Centuries after Senkovi’s death, octopus civilization flourishes. They have mastered the human technology he left behind, building sprawling underwater cities. Their society is emotionally driven and fluid; conflicts are often resolved through ritualized combat, during which their decentralized nervous systems—the emotional “Crown” of the octopus head and the logical “Reach” of their arms—exchange complex information subconsciously. A leader named Paul engages in such a fight with a rival, Salome; during the contest, he is swayed by her arguments and switches his allegiance. Despite their rapid technological and cultural evolution, Senkovi’s prohibition remains absolute: The sunken shuttle containing the Nodan parasite is left undisturbed.

Millennia later, the octopus civilization on Damascus is collapsing. The population has swelled to 39 billion, overwhelming the planet’s ecosystem and rendering their cities toxic. Widespread famine and pollution lead to constant, violent conflict. In one city, an octopus named Paul, grieving the death of his offspring from the poisoned water, incites a riot that tears his community apart. This scene is repeated across the planet as the civilization consumes itself.

A generation later, the conflict has escalated into space. An octopus named Salome commands a repurposed civilian transport in a battle over control of mining resources from the system’s asteroid belt. One of her fighter pilots, Rebekah, attacks another faction’s capital ship. She exploits a poorly repaired section of its hull, using a laser to cause a catastrophic depressurization that destroys the vessel. The resource wars among the octopus factions continue unabated.

Thousands of years later, an octopus named Lot, part of an orbital community of idealists who were driven from their home by the resource wars, has become a bitter radical. Forced to live on the dying planet below, he believes that only a powerful, transformative event can save his people. Fixated on the ancient legends of Senkovi, he comes to believe that the forbidden shuttle wreck contains not a plague, but a weapon. He leads a group of followers to the prohibited site and uses cutting drones to breach the shuttle’s hull. As seawater floods the ancient vessel, it awakens the Nodan parasite, which has been dormant inside in the shape of a human.

This chapter is written from the Nodan parasite’s perspective. It awakens in water, a new and confusing environment. Its memories of being human have degraded. It disperses, seeking new, complex hosts. When it infects the octopuses, it is baffled by their decentralized nervous systems. Its attempts to understand and control its hosts by targeting a single center fail, causing the host’s body to literally tear itself apart as each limb fights for control. The parasite learns nothing, but it replicates from the remains and continues its destructive quest for a comprehensible host.

The Nodan infection spreads like wildfire, causing the total collapse of the octopus civilization on Damascus. An orbital engineer named Solomon watches from his station at the top of a space elevator as billions of his species are consumed by the plague. Refugees flee to the orbital habitats, but they carry the infection with them. When a neighboring station is forced to destroy an infected hub in self-defense, Solomon realizes the orbital dwellers’ only hope for survival is total quarantine. He and the other administrators make the decision to sever the space elevator cables, abandoning the homeworld and its remaining inhabitants forever.

In the aftermath of the apocalypse, the surviving orbital octopus community endures. A scientist named Noah, convinced Damascus is a lost cause, organizes an expedition to the forbidden planet Nod. He and his colleagues, Ruth and Abigail, establish a research base in the derelict human station orbiting the planet. Ruth and Abigail hope to find a cure for the Nodan plague, while Noah secretly works to develop a method of interstellar travel. Their research leads them to capture a Nodan lifeform for study. Their activity is detected by a faction from the Damascus orbitals, who dispatch a warship to destroy them for breaking the ancient taboo. As the warship attacks, Noah activates his experimental device. It is a powerful weapon that instantly annihilates the enemy ship by displacing it across light-years of space. Seconds later, the station is struck by the warship’s last volley of projectiles and destroyed, killing Noah and his colleagues.