Roger Allam

self (narrator)

Annie Machon

Self - Former MI5 intelligence officer

Ben Macintyre

Self - Author of A Spy Among Friends: Kim Philby and the Great Betrayal

Dr. Helen Fry

Self - British Intelligence historian

Dita Gjuraj

Self

Tom Bower

Self

Roland Philipps

Self - Author of 'A Spy Named Orphan: The Enigma of Donald Maclean'

James P. Olsen

Self - Former Chief of Counterintelligence at the CIA

Miranda Carter

Self - Author of 'Anthony Blunt: His Lives'

Mikhail Petrovich Lyubimov

Self - Former KGB colonel

David Haig Thomas

Self (archive footage)

Adolf Hitler

Self (archive footage)

Harold Rickett

Self (archive footage)

Joseph Stalin

Self (archive footage)

J. Edgar Hoover

Self (archive footage)