Britain's Greatest Codebreaker

Ed Stoppard Alan Turing Henry Goodman Franz Greenbaum Paul McGann Himself - Narrator (voice) Asa Briggs Himself - Codebreaker, Bletchley Park Jean Valentine Herself - WRNS and Bombe Operator, Bletchley Park David Leavitt Himself - Alan Turing's Biographer Rolf Noskwith Himself - Codebreaker, Bletchley Park Dermot Turing Himself - Alan Turing's Nephew Christopher Morcom Himself - Christopher Morcom's Nephew (as Christopher Morcom QC) Ian Stewart Himself - University of Warwick (as Professor Ian Stewart)