'A Scandal in Bohemia' does not, as one may assume from the title, take place in Bohemia. Instead, it begins in the sitting-room of 221b. We find Holmes pondering a note from a prospective client. The client turns out to be the rather theatrical King of Bohemia.
The King has come to ask for Holmes' help with a delicate matter - a case of blackmail by an ex-lover. This is particularly problematic, as the King is about to marry to form an alliance, and his bride-to-be's family would not be pleased to discover his past indiscretion. It turns out that Irene Adler has a photograph of herself and the King together. Her plan, it seems, is to stop him from marrying another woman. We soon learn that she is a clever woman, having foiled several attempts to retrieve the incriminating photograph in the past.
After accepting a promise of any price he wished for the photograph, and a thousand pounds up front (a fantastic amount of money for the period), Holmes takes on the case and starts about his investigation.
As to how it all ends? Well, you'll have to read the story. Suffice it to say, results are mixed.
The King of Bohemia
Otherwise known as Wilhelm Gottsreich Sigismond von Ormstein, Grand Duke of Cassel-Felstein, and hereditary King of Bohemia. Let's call him 'The King', for ease of reference. He is described by Watson as 'a man of strong character, with a thick, hanging lip, and a long, straight chin suggestive of resolution pushed to the length of obstinacy'. Of course, this is straight after he describes him as a barbarian. So we can all form our own conclusions.
He is interesting, because this is the only instance in which we see Holmes directly interacting with royalty - and this is notable, because it becomes fairly obvious to us that Sherlock Holmes, great literary detective, is not especially impressed by the King's position. Indeed, he is outright disdainful of the man at the end, pointing out that Irene Adler is on a much different level to the King, and implying that she is indeed on a much higher one. Considering Holmes' usual opinion on women in general, this is a truly damning insult. Luckily, the King doesn't seem to notice.