In 1974, genius Philip Carvel meets an idealistic security services agent, Milner, at a secret forum of political, industrial, financial and academic leaders... by 1979, Carvel's losing his mind.

The final episode sees time running out. As a daring plan is formed, only one question remains - will the true secrets of Utopia finally be revealed?

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

Following the revelation that her father's alive, Jessica sets off to find him, with hostage Milner in tow. Wilson and Leah analyse their information and discover a far darker, more terrifying secret.

When five strangers from an online comic book forum gain possession of a cult graphic novel, they find themselves pursued by a shadowy organisation who are prepared to kill to track it down.

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.

A shocked Dugdale reluctantly agrees to harbour Jessica, but who should be scared of who? When Dugdale visits Jen and Alice in a secret prison it's clear he will do whatever The Network asks.

The gang feel the full weight of The Network's power as Grant is framed for a shocking crime. With nowhere else to turn, they are forced to make a new ally - but can she really be trusted?

The gang's attempt to disrupt The Network's plans backfires leaving one of them in danger. Arby's confession to Jessica has damaging repercussions while Becky is left with an impossible choice.

In the final episode the race is on to find out who is going to release the flu. The gang track down Dobri Gorski, where he tells them the names of the three people he trained to release the flu.

Ian and Becky are forced to face the terrifying reality of life on the run. Meanwhile, Dugdale is drawn deeper and deeper into a plot that threatens to have fatal consequences.

Hidden away in a derelict manor house, the group attempt to decipher the secret meaning of the manuscript. Will uncovering the identity of Mr Rabbit really allow them to return to their former lives?