

Alan Turing

Joan Clarke

Hugh Alexander

Detective Robert Nock

John Cairncross

Peter Hilton

Commander Denniston

Stewart Menzies

Jack Good

Sergeant Staehl

Superintendent Smith

Keith Furman

Charles Richards

Young Alan Turing

Christopher Morcom

Helen

Sherborne Student 1

Sherborne Student 2
Sherborne Student 3

Joan's Father

Joan's Mother

Teacher
Headmaster

MI6 Agent

Military Policeman
Margaret

Electrical Assistant
Woman in Crowd (uncredited)

Ministry Man (uncredited)

Wren (uncredited)
Dancer (uncredited)

Assistant Wren (uncredited)
Crossword Man in Pub (uncredited)

MI6 Agent (uncredited)
Joan Clarke's Friend (uncredited)

Bletchley Park Agent (uncredited)
Passerby (uncredited)
Military Policeman 3 (uncredited)

Civilian (uncredited)

Evacuee (uncredited)

Bletchley Park Operative (uncredited)
MI6 Agent (uncredited)

Police Sergeant White (uncredited)

Crossword Man (uncredited)
First Aid Nurse (uncredited)
German Pilot (uncredited)
German Spy Plane Pilot (uncredited)