Nihei, Tsutomu

"Sanakan attempts to destroy the Central A.I., as Mensab and her guardian knight, Seu, fight for the lives of the human residents they promised to protect. After the Central A.I. recklessly attempts to forward the whole of TOHA Heavy Industries, Kyrii and Cibo are left with a precious genetic sample from a very old human being. Wanting to test the genetic sample for signs of the Net Terminal Gene, Kyrii and Cibo make their way through an unofficial megastructure..."--Publisher website.

Davine Lu is attempting to access the Netsphere within an unofficial stratum of the megastructure, where temporary access can be granted even without a Net Terminal Gene. After a fierce battle, Pcell steals Cibo's precious capsule of human genetic information and forwards it to Davine Lu. After reuniting with Kyrii, Cibo and the provisional Safeguards try to retrieve the capsule before it's too late. As Davine Lu attempts to connect to the Netsphere, the Administration slows down his connection speed to allow Cibo to give virtual chase and for Dhomochevsky to battle the Silicon Life in base reality. As a final act, Davine Lu steals high-level data and uses Cibo's body to create an unstoppable Level 9 Safeguard...

"While the Sidonia girds up to take the battle to the Greater Cluster Ship, a lethal threat that has been brewing within the family erupts"--Back cover.

"A lone seed ship, the Sidonia, has arrived in the Lem star system, ten centuries since the obliteration of Earth. The massive, nearly indestructible, yet barely sentient alien life forms that continued to pose an existential threat are now aided and abetted by humanity's best scientific mind"--Back cover.

Captain Kobayashi becomes commander of the seed ship, and Tanikaze gets a new house in it.

The war with Gauna continues, a humanish Gauna is analyzed, and secrets are revealed about the Sidonia.

Even though the "Sidonia" has gained significant advances in technology, the seed ship still seems out matched by the Gauna, who adapt so rapidly that physical science may not be able to keep up--something more drastic is needed.

A forbidden room is unsealed and all at once the heroic pilot Saito discovers a deceptive avatar of his onboard. Then, an incoming asteroid forces the "Sidonia's" mobile units to enter a positive-gravity environment to skirmish. Assistant Commander Yuhata Midorikawa's mettle is tested.

Tensions rise as some crewmen on the "Sidonia" feel that it is humanity's aggressive posture towards the alien Gauna that has made the Gauna so hostile against them. Meanwhile Hero Tanikaze and his friend Shinatose are promoted, just when the heir of the Kunato family succumbs to dangerous experimentation.

When the Sidonia engages a new type of Guana that is winning the war against the young pilots, rookie pilot Nagate Tanikaze devises his own plan of attack to protect his squadron. Meanwhile, the history of the Guana is revealed and Tanikaze encounters a jealous rival.