"The Reichenbach Fall" is the third and final episode of the second series of the BBC television series Sherlock. It was written by Stephen Thompson and stars Benedict Cumberbatch as Sherlock Holmes, Martin Freeman as Dr John Watson, and Andrew Scott as Jim Moriarty. The episode deals with Moriarty's attempt to undermine the public's view of Sherlock and drive him to suicide. The episode was first broadcast on BBC One and BBC One HD on 15 January 2012. It attracted 9.78 million viewers, and critical reaction to the episode was positive. After the episode was aired, there was also much online and media speculation, which focused on Sherlock's death.

Inspired by "The Final Problem" by Sir Arthur Conan Doyle, the episode follows Moriarty's plot to discredit and kill Sherlock Holmes, also heavily using elements from the film The Woman in Green. The title alludes to the Reichenbach Falls, the location where Holmes and Moriarty supposedly fall to their deaths in the original story. Some sequences in the episode that are set at the Tower of London were filmed at Cardiff Castle. Other locations used include Newport Cemetery, Tredegar House and Cardiff City Hall, as well as other areas around Cardiff including Broadway and Cardiff Bay.

John Watson is in his first meeting with his therapist after eighteen months. Struggling to explain his visit, he eventually chokes out the words, "My best friend, Sherlock Holmes, is dead." The episode flashes back to three months earlier, with Sherlock receiving plaudits and gifts from various people for whom he has solved cases, along with much unwanted media attention, especially for his recovery of a Turner painting of Reichenbach Falls.

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