he has the information he requires. Irene Adler Irene Adler is a retired American opera singer and actress who appears in "A Scandal in Bohemia". Although this is her only appearance, she is one of only a handful of people who best Holmes in a battle of wits, and the only woman. For this reason, Adler is the frequent subject of pastiche writing. The beginning of the story describes the high regard in which Holmes holds her: Five years before the story's events, Adler had a brief liaison with Crown Prince of Bohemia Wilhelm von Ormstein. As the story opens, the Prince is engaged to another. Fearful that the marriage would be called off if his fiancée's family learns of this past impropriety, Ormstein hires Holmes to regain a photograph of Adler and himself. Adler slips away before Holmes can succeed. Her memory is kept alive by the photograph of Adler that Holmes received for his part in the case. Knowledge and skills Shortly after meeting Holmes in the first story, A Study in Scarlet (generally assumed to be 1881, though the exact date is not given), Watson assesses the detective's abilities: In A Study in Scarlet, Holmes claims to be unaware that the earth revolves around the sun since such information is irrelevant to his work; after hearing that fact from Watson, he says he will immediately try to forget it. The detective believes that the mind has a finite capacity for information storage, and learning useless things reduces one's ability to learn useful things. The later stories move away from this notion: in The Valley of Fear, he says, "All knowledge comes useful to the detective", and in "The Adventure of the Lion's Mane", the detective calls himself "an omnivorous reader with a strangely retentive memory for trifles". Looking back on the development of the character in 1912, Conan Doyle wrote that "In the first one, the Study in Scarlet, [Holmes] was a mere calculating machine, but I had to make him more of an educated human being as I went on with him." Despite Holmes's supposed ignorance of politics, in "A Scandal in Bohemia" he immediately recognises the true identity of the disguised "Count von Kramm". At the end of A Study in Scarlet, Holmes demonstrates a knowledge of Latin. The detective cites Hafez, Goethe, as well as a letter from Gustave Flaubert to George Sand in