As a major crisis threatens the stability of the UK, Prime Minister Robert Sutherland and his close team assemble the emergency committee COBRA in an effort to combat the situation.

With the nation experiencing one of the worst crises in UK history, the Prime Minister and his team are forced to work around the clock. Anna reconnects with a face from her past.

As the country continues to face dark days, the Prime Minister, Anna, Fraser and their teams pay a visit to the worst affected area. Archie’s rhetoric threatens to cause more problems for everyone.

As questions are asked about the Prime Minister’s personal life, Anna seeks the help of intelligence chief Eleanor James. A new threat rears its head as public sentiment grows ever turbulent.

With the crisis worsening, Fraser deals with issues in his personal life. The Prime Minister is forced to consider more extreme measures to retain control and apply order over the country.

As the crisis reaches boiling point, Fraser and his team reach the endgame, while the Prime Minister and Anna are forced to fight for their political lives with Archie firing his first shots.