- Tom Goodman-Hill - Sergeant Staehl
- Steven Waddington - Superintendent Smith
- Ilan Goodman - Keith Furman
- Jack Tarlton - Charles Richards
- Alex Lawther - Young Alan Turing
- Jack Bannon - Christopher Morcom
- Tuppence Middleton - Helen
- Dominic Charman - Sherborne Student 1
- James G. Nunn - Sherborne Student 2
- David Charkham - Joan's Father
- Victoria Wicks - Joan's Mother
- Andrew Havill - Teacher
- Laurence Kennedy - Headmaster
- Tim van Eyken - MI6 Agent
- Will Bowden - Military Policeman
- Miranda Bell - Margaret
- Tim Steed - Electrical Assistant
- Bartosz Wandrykow - Crossword Enthusiast
- Hayley Joanne Bacon - Woman in Crowd (uncredited)
- Nicholas Blatt - Ministry Man (uncredited)
- Ancuta Breaban - Wren (uncredited)
- Alex Corbet Burcher - Dancer (uncredited)
- Grace Calder - Assistant Wren (uncredited)
- Richard Campbell - Crossword Man in Pub (uncredited)
- Daniel Chapple - MI6 Agent (uncredited)
- Lisa Colquhoun - Joan Clarke's Friend (uncredited)
- Alexander Cooper - Bletchley Park Agent (uncredited)
- Leigh Dent - Passerby (uncredited)
- Sam Exley - Military Policeman 3 (uncredited)
- Denis Koroshko - Civilian (uncredited)
- Debra Leigh-Taylor - Evacuee (uncredited)
- Stuart Matthews - Bletchley Park Operative (uncredited)
- Joseph Oliveira - MI6 Agent (uncredited)
- David G. Robinson - Police Sergeant White (uncredited)
- Mark Underwood - Crossword Man (uncredited)
- Josh Wichard - German Pilot (uncredited)
- Phil Booth
-
Graham Moore
- Teddy Schwarzman
- Peter Heslop
- Nina Gold
- John Midgley
- Dan Green
- Kirsty Whalley
- Lee Walpole
- Peter Burgis
- Alexandre Desplat
Capítulo disponible en las siguientes plataformas:
