I was prompted to seek out George Milner's The Crime Against Marcella, which dates from 1963, after reading a laudatory review by Francis Iles, who was no mean judge of a book. Milner was really George Hardinge, a noted publisher, who was the editor of (among many other crime writers) Julian Symons. He also edited the Winter's Crimes anthologies before handing over to Hilary Watson, aka Hilary Hale, another editor of distinction.
Milner was a good enough novelist to earn election to the Detection Club, and this book is fluently written. In a distant way, it seems to me to be an update for the Sixties of the type of ironic crime story in which Francis Iles himself specialised. The tone is reminiscent of that to be found in other crime books of similar vintage by the likes of John Bingham and Symons.
Milner plays a game with the structure of his story, while his title is ambiguous. The scene is set by internal memoranda from Scotland Yard, which discuss the disappearance and presumed murder of a young married woman called Marcella Pemberton, but the bulk of the novel is a first-person narrative by her husband. Jim Pemberton explains how he became besotted with Marcella, and the various complications that ensued from the fact that his best friend and business partner was equally interested in her.
I figured out the principal plot twist some time before the end of this short, snappy mystery, and my main reservation about the book is that it reads rather more like a novella than a full-length story. But it's agreeably written, and a good example of the way in which writers of the time were trying to update the conventional puzzle story with a focus on character and exploration of the nature of sexual repression and jealousy. An obscure book nowadays, but well worth reading.