After viewing the 1959 adaptation of John Buchan's The Thirty-Nine Steps, I re-watched the 1935 Hitchcock version (superior) and then realized I'd never read the short novel. so I did, today.
Richard Hannay, retired and bored, wishes something would happen to him in London. So a freelance spy with knowledge of a war being foisted by an evil German cabal angling to drag England into a fighting war about September of 1914 has come close to setting their plan in motion. Unfortunately the spy winds up pinned to the bedroom floor of Hannay's London flat, and our hero determines to flee to the wilds of Scotland, where the wee greebin braes and the multoons will nae reveal a prodigal son tae the wicked Germans.
And they don't. By pure chance, Hannay elects to ask for shelter from the one man, who unknown to him is the mastermind behind the spy plot. He throws Hannay into a warehouse that was used to house explosives. He uses one to blast the west wing to smithereens, along with a few of his captors, though the Germans are omnipotent and know all.
In the end, by the skinniest teeth he owns, Hannay tricks the Germans, eludes the mooks, and saves England, which is immediately tumbled into WWI, which Hannay thinks may make him happier if it allows him to escape boredom.
Anti-Semitism slips in--some characters believe the Jews are leading the world into war to profit by it--but it's not as strong and deep as the bigotry in, say G.K. Chesterton's The Man Who Knew Too Much. One can certainly see the ancestor of James Bond and especially Jason Bourne, both of whom tend to do a butt-load of running to catch or to elude the bad guys. That is precisely the pattern established in Buchan's Hannay novels. Fine but don't take it seriously.
Oh, and contrary to the movies, the book has no bloody sheilas, at least none who affect the plot.
You'll be needing a humorous read after all that! 