It is notable for being one of only two Arthur Conan Doyle Holmes stories, aside from a couple of humorous vignettes, to be written in third person. The other is "His Last Bow". "The Mazarin Stone" was written this way because it was adapted from a stage play, "The Crown Diamond", in which Watson hardly appeared. Its adaptation from the theatre also explains why the action in this story is confined to one room. The plot twist in which Holmes reveals he had been listening to the two criminals as they spoke freely would also not have been possible using a first person narrative.