Secret histories of Bletchley Park Feature films, it is true, are not history lectures. Yet new generations derive from them indelible images of what they mistake for history. If few care that Braveheart showed Scots in kilts long before they developed, it matters more when versions of recent history do down reputations. Relatives of men who died at Gallipoli this week inveighed at Russell Crowe's version of events. Now grandchildren of a hero of Britain's code war have written to the Telegraph to complain at the film The Imitation Game "taking a side-swipe at Commander Alastair Denniston." This was the man who brought back Enigma secrets from Poland and recruited Alan Turing. As Sir Harry Hinsley, his fellow cryptanalyst, wrote, Denniston, by his "trust in subordinates and his charm, set his stamp on the character of Bletchley Park." Depicting him as a hindrance is a cruel caricature.