I was in 'Das Kriminalhaus' in Hillersheim (Germany) which has a huge collection of second-hand detectives. They are of course mostly in German, which I can't read, but with a scattering of English books amongst the collection. I was surprised to come across this book as I didn't know that Irus Murdoch had written a detective. An indeed this turns out to be a far from conventional detective; the murder is not what you think, the police are not involved and the plot is subservient to the characters. Nevertheless, unlike some Iris Murdoch books, there is a substantial plot, which carries you along whilst you enjoy the weird set of characters and the language.
It is not always easy to read. She writes paragraphs in Latin and French without even a footnote to explain what they are about. She uses words like "rebarbative" (which means ugly, seeing you ask), which I had to look up. I suppose that is to be expected from a philosophy professor writing in 1968.
There is one odd mistake. There is seaweed growing in the cave completely in the dark. Seaweed can grow in low light intensities, but it is a plant, it needs light. Seeing she happily bands about Latin names of garden plants, I would have thought she would have known that.
Although written in 1968, in some ways it feels much older. People have servants; cooks and cleaners and drivers. All the main characters are upper class, or at last upper-middle class; working people are just the supporting cast. I guess that was her world.
Despite being so dated (which even gave it a certain charm), the book was still an enjoyable read and also the mystery element was quite fun.