This is a 1915 novella by John Buchan. John Buchan, 1st Baron Tweedsmuir, GCMG, GCVO, CH, PC was a Scottish novelist, historian, and Unionist politician who served as Governor General of Canada, the 15th since Canadian Confederation.
I say! What a dashed ripping yarn old chap! (I stole that from a review on Goodreads.) I usually like books from this era, but frankly, for me, this one read like a YA boy’s thriller.
A guy returns to England from Rhodesia, and is bored. There is a spy living in his apartment house, and who ends up dying in Hannay’s apartment, and our boy is on the run from the police who think he did it. He has found a coded notebook of the spy, and it talks of an important person getting killed which would start off a great war. There were was something about the counterspies who will escape by means of the thirty-nine steps.
On the run, Hannay decides to go to Scotland, but the police and the other spy guys get wind of him there, and he experiences a lot of hair’s breadth escapes, a lot of which includes improbable disguises. Makes you think those other spy guys were pretty incompetent.
Well, spoiler time, Hannay is not in time to alert the authorities, and that important guy gets killed, but Hannay is able to thwart the killers’ escape. What comes to be called the Great War starts two days later.
There are a bunch more books in this series. But not for me. I am going to leave improbable disguise thrillers, and get back to improbable space opera thrillers. Eh. To each her own, right?