2. The Blind Banker

Sherlock is hired by an old friend to investigate a mysterious break-in at a bank in the City. He discovers that symbols spray-painted onto an office wall are a coded message intended for an employee of the bank, who is later discovered dead in his flat. The next day, a journalist is killed and the same symbols are found nearby. Sherlock and John follow a trail of clues that link the two dead men to a Chinese smuggling ring, who are trying to retrieve a valuable item that one of the dead men stole.

Sherlock eventually cracks the coded message based on Suzhou numerals and a book cipher, but not before John and his date, Sarah, are kidnapped by the criminals, who believe that John is Sherlock. Sherlock rescues them, but the leader of the gang escapes. Later, the leader of the gang is in communication with her superior, who is identified by the initial "M". She is then shot by a sniper. Loosely based on the short story " The Adventure of the Dancing Men ", the storyline also incorporates elements from other Sherlock Holmes stories; the concept of coded messages, the markings on the feet of the Black Lotus members and the plot of escaping a secret society, then being tracked to and killed in England all feature in The Valley of Fear. A murder victim being found inside a locked room, accessible only by climbing, alludes to The Sign of the Four.