Utopia

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.

In the present day, Jessica has been held captive by Milner who has tortured her in a desperate attempt to find out just what adjustment Carvel made to Janus. Ian and Grant are desperately searching for Becky. The Network is planning V Day- a strategy to vaccinate the whole world from Russian flu and Geoff is being forced to sell the idea to the nation.

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.

A shocked Dugdale reluctantly agrees to harbour Jessica. Jessica is searching for Ian, as is Milner who is convinced he will lead her to Carvel.

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.

The gang face a race against time to work out who is going to release the flu, and stop them in order to prevent global disaster.