A KGB plot to attack the UK has plunged Britain into a state of emergency. Charles, a young MI6 spy, is asked to revive an old friendship with Russian diplomat Viktor. But Viktor has his own agenda.
Charlie Cox
Romola Garai
Andrew Scott
Christian McKay
Simon Russell Beale
Richard McCabe
Olivia Grant
Geraldine James
Tessa Peake-Jones
Robert Ashby
Alec Utgoff
Charlotte Randle