1974, England - Scientist Philip Carvel has a fateful meeting with a young woman, Milner, bonding over a shared ideology their influence on each other will lead to the creation of a virus - their solution to the world's over-population.
3 months after the destruction of the manuscript, things have been quiet for Ian, Becky and Grant. Believing the Network to be finished, they each try to resume some semblance of normality, but the Network's plan is only just beginning.
The gang are on the run and find a precocious young hacker, who uncovers the key to The Network's new plan: a real global outbreak of weaponised Russian flu that will prompt the entire world to take up their vaccine on V Day.
With the revelation that her father is alive, Jessica and Milner set off to find him. Arby takes Grant and Anton to a place from his past, a remote mountainside where he came as a child.