Nicol Williamson as Maurice Castle

Richard Attenborough as Colonel John Daintry

Derek Jacobi as Arthur Davis

John Gielgud as Brigadier Tomlinson

Iman as Sarah

Joop Doderer as Cornelius Muller

Robert Morley as Doctor Percival

Ann Todd as Castle's Mother

Anthony Woodruff as Dr Barker

Keith Marsh as Porter

Gary Forbes as Sam

Angela Thorne as Lady Mary Hargreaves

Tony Haygarth as Buffy

Cyd Hayman as Cynthia

Paul Seed as Shop Assistant

Ken Jones as Messenger

Fiona Fullerton as Elizabeth

Tony Vogel as Matthew Connolly

Martin Benson as Boris

Adrienne Corri as Sylvia

Edward Dentith as Edward

Marianne Stone as Matron

Giles Watling as Colin

Frank Williams as Bellamy

Tom Chatto as Gen. Phillips

Sean Caffrey as Policeman

Clifford Earl as Ferguson

Sylvia Coleridge as Mrs Halliday

Denys Hawthorne as Insp. Butler

Glenna Forster-Jones as Black Prostitute

Morris Perry as Scientist

Richard Vernon as Sir John Hargreaves

Walter Hinds as Van Donck

Philip Chege as Black Man

Norbert Okare as Questioner

Vicky Udall as Castle's Secretary

Brian Epson as Judge

Leon Greene as Tall Man

Robert Dorning as Jameson

Patrick O'Connell as Reader

Raewyn Blade as Secretary

Boris Isarov as Agent

Paul Curran as Halliday

Chantal Gray as Stripper

Jill Goldston as NATO Lab Worker (uncredited)