WE return to the foggy (多雾的) Victorian London of the Holmes stories for our final detective fiction, The Ruby in the Smoke. Indeed, the novel has other similarities with the stories of Conan Doyle. As in The Sign of the Four, the plot involves India, as it is home to the ruby (红宝石) of the title. As it unfolds (展开), the story introduces an Indian Maharajah and a criminal gang (团伙). The themes Philip Pullman focuses on are passion (热情), love, and wealth.