The following exchange comes from Alan Bennett’s glorious Forty Years On, Act Two:

Leithen: Is he sane?
Sandy: Sane? He is brilliantly sane. The second sanest in Europe. But like all sane men he has at one time or another crossed that thin bridge that separates lunacy from insanity…

Audiences watching the play’s first run in 1968 would probably have spotted the nature of the parody much more readily than theatregoers fifty-one years on would. Bennett is evoking the world of ‘Sapper, Buchan, Dornford Yates, practitioners in that school of Snobbery with Violence that runs like a thread of good-class tweed through twentieth-century literature’.

Buchan and co were, if we are to credit the Molesworth books (and we should), the authors of ripping yarns about clean-limbed heroes and dastardly foreign johnnies that all schoolboys read before reaching puberty and