Student Saara wins an internship at GCHQ, but when the UK's internet goes down, she finds herself on the frontier of high-stakes cyber warfare.
Saara unravels a dubious invitation. Is she getting closer to the truth - or a trap?
Saara's classmate Vadim returns to St Petersburg. He reluctantly takes a covert job and soon becomes the victim of his own success as his allegiances are put to the test, leading him to a risky stunt.
With Danny unconvinced by Saara's exchange with a whistleblower, she's in a difficult position, but a revelation from Kathy forces Saara's hand. Meanwhile, Marina takes up a new opportunity in London.
The UK general election result prompts unrest, while Saara makes a devastating discovery.
As the truth becomes clear, Saara and her classmate join forces to prevent a war.
