Death at the Chase (1970) by Michael Innes
It's a very long time indeed since I've read a Michael Innes novel, and I'd forgotten his extraordinary self-satisfied pomposity of narrative and the fact that it was for good reason that I'd never been able to make any headway with the non-mystery novels this Oxford don wrote under his real name, J.I.M. Stewart. If you want a flavour of the tone and exaggerated plundering of vocabulary, you could do worse than read the sections of Michael Innes parody interpolated by Dave Langford into our spoof disaster novel Earthdoom (1987; shortly to be reissued by those enterprising folks at DarkQuest Books). (Generally speaking Dave did the Innes parodies in that book, I did the McBain ones.)
In Death at the Chase the style does ease up a bit in places, usually when Bobby Appleby, son of series detective John Appleby, is taking centre stage in place of his father; but certainly the first few chapters read in themselves like a parody. This may have been because Innes realized he was having to stretch a short story's worth of plot quite extravagantly in order to fill out a novel, and thus resolved never to use one word when a score or more -- or preferably a few paragraphs -- would do every bit as well. The plot is certainly pretty simple. John Appleby, now Sir John, has retired from the force to enjoy rural splendour. He discovers that one of his neighbours, the eccentric Martyn Ashmore, believes that an attempt is made on his life once a year by vengeant members of the French Resistance, still enwrathed after all these years because he gave up information to the Nazis under torture. In due course Ashmore is indeed bumped off, but the solution to the mystery proves to lie a lot closer to home.
Still, at least this one's better than Appleby's End, memory of which still strikes a chill in my soul even decades after I read it . . .