Fraser and his team reach the endgame in their mission.
Robert Carlyle to return as PM Robert Sutherland.
Sutherland is forced to fight for his political life.
Fraser says goodbye to his father.
Sutherland is forced to consider more extreme measures.
Public sentiment grows more turbulent.
A new threat rears its head.
The country continues to face darkness.
Sutherland decides to visit the worst affected area in Northumberland.
Anna reconnects with Edin.
Sutherland and his team are forced to work around the clock.
COBRA is assembled to deal the effects of an incoming solar storm.