Holmes es llamado por un caballero enmascarado. Se presenta como el conde Von Kramm, un agente de un cliente adinerado, pero Holmes deduce rapidamente que se trata de Wilhelm Gottsreich Sigismond von Ormstein, gran duque de Cassel-Felstein y rey hereditario de Bohemia. El rey, arrancandose la mascara, lo admite. El caso es el siguiente: el rey esta prometido con Clotilde Lothman von Saxe-Meningen, una joven y aburrida o divertida, segun la persona, princesa escandinava, pero los suegros del rey tendrian una opinion muy mala de el si alguna prueba de su relacion formal con una cantante de opera llamada Irene Adler, originaria de Nueva Jersey, se les fuera revelada. Desafortunadamente, eso es lo que la dama esta intentando hacer, aunque aparentemente no por dinero, ya que los agentes del rey han intentado comprar la prueba. Tambien han allanado la casa de Irene Adler para intentar encontrar la prueba. La prueba es una foto descrita a Holmes como de tamano exposicion, y por lo tanto demasiado grande para poder llevarla encima, que muestra al rey (entonces era el principe heredero) e Irene Adler. El rey le da a Holmes 1000 libras (83.000 libras de 2008)1 para cubrir cualquier gasto, aunque dice que le daria una provincia de su reino por recuperar esa fotografia. Holmes queda con Watson en el 221 de Baker Street a las tres de la tarde del dia siguiente. While the currently married Dr. Watson is paying Holmes a visit, a visitor arrives, introducing himself as Count Von Kramm, an agent for a wealthy client. However, Holmes quickly deduces that he is in fact Wilhelm Gottsreich Sigismond von Ormstein, Grand Duke of Cassel-Felstein and the hereditary King of Bohemia. Realizing Holmes has seen through his guise, the King admits this and tears off his mask. It transpires that the King is to become engaged to Clotilde Lothman von Saxe-Meiningen, a young Scandinavian princess. However, five years previous to the events of the story he had a liaison with an American opera singer, Irene Adler, while she was serving a term as prima donna of the Imperial Opera of Warsaw, who has since then retired to London. Fearful that should the strictly principled family of his fiancee learn of this impropriety, the marriage would be called off, he had sought to regain letters and a photograph of Adler and himself together, which he had sent to her during their relationship as a token. The King's agents have tried to recover the photograph through sometimes forceful means, burglary, stealing her luggage, and waylaying her. An offer to pay for the photograph and letters was also refused. With Adler threatening to send them to his future in-laws, which Von Ormstein presumes is to prevent him marrying any other woman, he makes the incognito visit to Holmes to request his help in locating and obtaining the photograph."