Intense and emotionally charged Cold War thriller set in 1974 based on the novel by Alan Judd. As the three day week, petrol rationing and industrial strife plunge Britain into a state of emergency, MI6 trainee spy Charles Thoroughgood is asked to reconnect with an old university friend, Russian diplomat Viktor Koslov, with a view to 'turning' him. Viktor has his own agenda, though, and reveals a shocking truth about Charles's own family that threatens to derail him, both personally and professionally. He is catapulted into a dangerous personal odyssey to uncover the truth but finds himself drawn into a lethal KGB plot to mount an attack within the UK. His life is further complicated by a relationship with the wife of another agent, which forces him to realise that betrayal can take many forms.