Years later, the gleisner Karpal, using a gravitational-wave detector, determines that a binary neutron star system in the constellation of Lacerta has collapsed, releasing a huge burst of energy. Previous predictions portrayed the system's stable orbit as likely to last for another seven million years. By analysing irregularities in the orbit, Karpal discovers that the devastating burst of energy will reach Earth within the next four days. Yatima and Inoshiro return to Earth to urge the fleshers—gathered in a conference—either to migrate to the polises or at least to shelter themselves. Many fleshers reject this advice, or fail fully to appreciate its urgency quickly enough. Stirred up by a paranoid Static diplomat, many fleshers suspect that Yatima and Inoshiro have come to trick or coerce them into "Introdus", or mass-migration into the polises, involving masses of virus-sized nanomachines that dismantle a human body and record the brain's information states as it is chemically converted into a crystalline computer. The gamma ray burst reaches Earth shortly after the conference, destroying the atmosphere and causing a mass extinction. The gleisners and the Coalition of Polises survive the burst, thanks to cosmic radiation hardening. Over the next few years, Yatima and other citizens and gleisners attempt to rescue any surviving fleshers from slow suffocation, starvation, or poisoning by offering to upload them into the polises.