Character Name : Himself - Narrator

Original Name : Steven Mackintosh

Gender : Male

Character Name : Gordon Welchman (voice)

Original Name : Brian Deacon

Gender : Male

Character Name : Herself - Gordon Welchman's Daughter

Original Name : Rosamund Welchman

Gender : Male

Character Name : Himself - Ex-Head of Hut 6, Bletchley Park (1939-1941) (archive footage)

Original Name : W. Gordon Welchman

Gender : Male

Character Name : Himself - Author, 'The Secret Life of Bletchley Park'

Original Name : Sinclair McKay

Gender : Male

Character Name : Himself - Veteran, Hut 6

Original Name : Jimmy Thirsk

Gender : Male

Character Name : Himself - Veteran, Hut 6

Original Name : Asa Briggs

Gender : Male

Character Name : Herself - Veteran, Hut 6

Original Name : Jane Fawcett

Gender : Male

Character Name : Himself - GCHQ Historian and Former Analyst

Original Name : Tony Comer

Gender : Male

Character Name : Himself - Vice President, Wolfson College, Cambridge (as Prof John Naughton)

Original Name : John Naughton

Gender : Male

Character Name : Himself - Chairman, Bletchley Park Trust, and Former Chief, MI6 (as Sir John Scarlett KCMG OBE)

Original Name : John Scarlett

Gender : Male

Character Name : Herself - Gordon Welchman's Granddaughter

Original Name : Jennifer Welchman

Gender : Male

Character Name : Himself - Former President, The MITRE Corporation

Original Name : Robert R. Everett

Gender : Male

Character Name : Himself - Gordon Welchman's Colleague

Original Name : Eric Ellingson

Gender : Male

Character Name : Himself - Gordon Welchman's Colleague

Original Name : Larry Hill

Gender : Male