Alan Turing

Ed Stoppard

Acting

Franz Greenbaum

Henry Goodman

Acting

Himself - Narrator (voice)

Paul McGann

Acting

Himself - Codebreaker, Bletchley Park

Asa Briggs

Acting

Herself - WRNS and Bombe Operator, Bletchley Park

Jean Valentine

Acting

Himself - Alan Turing's Biographer

David Leavitt

Writing

Himself - Codebreaker, Bletchley Park

Rolf Noskwith

Acting

Himself - Alan Turing's Nephew

Dermot Turing

Acting

Himself - Christopher Morcom's Nephew (as Christopher Morcom QC)

Christopher Morcom

Acting

Himself - University of Warwick (as Professor Ian Stewart)

Ian Stewart

Acting