Dan breaks into Archie's home, demanding that Robert resign from his post of prime minister or he will resort to using the weapon.

COBRA is assembled when fresh disaster strikes, as a breach at Dover port suggests an insidious threat. The PM's strategy is tested by an online activist.

With the nation sliding further and further towards anarchy, Rachel faces difficult questions about Ellie. Meanwhile, Fraser says goodbye to his father and grows closer to Francine. And as the influence of “People’s Justice” grows ever-powerful, Sutherland is forced to consider more extreme measures to retain control of the country.

Following devastation in Kent and the cyber-attack which continues to jam communications, the Prime Minister convenes an emergency COBRA meeting.

While the government frantically launches a search operation to recover a stolen weapon, Dan and his group of mercenaries threaten to use it unless their demand for a ransom gets met.

The government faces intense scrutiny for legislating an anti-protest bill deemed to be too aggressive, leading to police forces deciding to go on an unofficial strike in response.

With the knowledge that his daughter is alive, Robert Sutherland turns his focus on handling the aftermath of the sinkhole collapse and dealing with the abduction of Princess Yadira.

With the nation in the full grip of the crisis and experiencing the worst blackout in the history of the UK, Sutherland and his team are forced to work around the clock to restore power. Meanwhile Anna reconnects with Edin, but this dalliance with her past love becomes more dangerous than she anticipates.

Robert and Anna return to COBRA to try and devise an effective strategy against members of an environmental protest group who are blocking traffic from going through a railway tunnel.

Following the sinkhole collapse, Robert and Rachel hurry to the site in the hope that Ellie might still be alive. Unbeknownst to them, Ellie has made a shocking discovery underground.