Recruited by the Russians during their days at Cambridge, three young Englishmen rise to become high-ranked MI5 agents until their exposure in 1949.
as Kim Philby
as Guy Burgess
as Donald Maclean
as Graves
as Helenus Milmo
as Pattterson
as Aileen Philby
as Major Sansom
as Peterson
as Reed
as Sir Stewart Menzies
as Volkov
as Herbert Morrison
as Skardon
as Marcus Lipton
as Melinda Maclean