• E1
• 0 hrs 47 min
• 30th June 2022

A young intern's first day at GCHQ coincides with a major cyberattack on the UK. To win her superiors' trust, she breaks ranks to analyse the malware code without permission and uncovers a greater threat missed by others.

• E2
• 0 hrs 47 min
• 7th July 2022

Saara befriends John, a veteran GCHQ staffer, and seeks help from Gabriel in decrypting a message in the virus. Danny signs off on Saara attending a cyber conference with US agent Kathy, aware that Russian intelligence will also be there.

• E3
• 0 hrs 56 min
• 14th July 2022

Vadim returns to Russia where his allegiances are tested, leading him to a risky stunt.

• E4
• 0 hrs 47 min
• 21st July 2022

With Saara in a difficult position, a revelation forces her hand. Marina moves to London.

• E5
• 0 hrs 47 min
• 28th July 2022

Signs of irregularity in the UK general election result prompt political unrest, and the nation's relationship with its allies is threatened. Saara makes a devastating discovery.