Although he is dead now, Mr. Rafiel (from [b:A Caribbean Mystery|31300|A Caribbean Mystery (Miss Marple, #10)|Agatha Christie|https://d.gr-assets.com/books/1309280346s/31300.jpg|937152]) writes Marple and asks for her help in solving a mystery, but he does not reveal what he wants her to do. Marple accepts the challenge and joins a tour of British famous houses and gardens arranged by Mr Rafiel, while trying to figure out what she is supposed to do.

I am always amazed by Christie's endless ideas to write different crime stories using the same mould. I guessed the plot early on, but it does not affect the reading because Marple's "adventures" are always entertaining to read.