Saara wins an internship at GCHQ, but when the UK's power goes down, she finds herself on the frontier of high stakes cyber warfare.

Saara finds a suspicious line of encrypted text within the virus's code and unravels a dubious invitation. Is she getting closer to the truth or falling into 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.

Saara cannot betray her source but Kathy has information that will force her hand.

Amid civil unrest, Saara is devastated to learn the identity of a mole inside GCHQ.

Saara and Vadim join forces to uncover the hidden code and try to prevent a war.