A masked man calls, on confidential business, and Holmes quickly recognizes the visitor as the King of Bohemia. The King is planning for himself a dynastic marriage and is worried about a compromising photograph in the possession of his American former mistress. He wants Holmes to get it back for him.In outwitting the lady, Irene Adler, Holmes goes to great lengths - and at the end of the affair Watson comes to the conclusion that his friend is himself smitten.