The Rasp, my Forgotten Book for today, was the first crime novel published by Philip MacDonald solo and under his own name (he'd previously co-written two books with his father). It appeared in 1924, when he was still in his early twenties, and it introduced Colonel Anthony Gethryn, who was to become one of the more popular "great detectives" of the Golden Age.
The first thing to say about this book is that it's a very assured performance, especially considering the youth and inexperience of its author. Yes, there are flaws (the explanation of the puzzle at the end is excessively long, for instance, and the killer's insanity is not adequately foreshadowed) but it really is an excellent example of the breezy Golden Age whodunit. MacDonald's writing is invariably energetic - in fact, in some books he produced later, it seems rushed - and he carries his readers along, so that we don't worry too much about the improbabilities of the plot.
The book is sometimes described as a "locked room mystery", because John Hoode, a cabinet minister, is found dead in his locked study; however, there is an open window, so this is by no means an "impossible crime". It's a tricky one to solve, nonetheless, and although the police arrest someone, Gethryn becomes convinced that the man is innocent, and has been framed.
I've admired MacDonald ever since reading a reprint of Gethryn's second case, The White Crow, in my teens, and I really enjoyed this whodunit. I have a facsimile dust jacket of the first edition, and I also love the publishers' blurb: " all the subsidiary characters, especially the ladies, usually the weak spot in detective fiction are drawn with humour and insight". They don't write blurbs like that any more! Nor do they write books quite like The Rasp any more. But if you like Golden Age fiction, with all its strengths and limitations, there is every chance you'll like this one.