Characters played by Derek Jacobi
Alan Turing
Characters played by Alun Armstrong
Mick Ross
Characters played by Blake Ritson
Christopher Morcom
Characters played by William Mannering
Young Alan Turing
Characters played by Prunella Scales
Sara Turing
Characters played by Julian Kerridge
Ron Miller
Characters played by Harold Pinter
John Smith
Characters played by Richard Johnson
Dilwyn 'Dilly' Knox
Characters played by Amanda Root
Patricia 'Pat' Green
Characters played by Scott McKinstry
Smoker