The second series' final episode, "The Reichenbach Fall", was based upon [COLOR="Red"](spoiler i hvit skrift)[/COLOR][COLOR="White"]The Final Problem, in which Sherlock and Moriarty plunge to their deaths (later, The Adventure of the Empty House reveals that Holmes faked his death, though Conan Doyle had meant to kill him off), but Steven Moffat felt that he and co-creator Mark Gatiss had outdone Conan Doyle in their version of Holmes' fall and Moffat added that, in that much-discussed sequence, there was still "a clue everybody's missed."[/COLOR] After the end of the final episode of the second series, Moffat and Gatiss both announced on Twitter that a third series was commissioned at the same time as series two. Steven Moffat has said that he is hoping the series will be screened "hopefully before the year's out.", though this has been contested by executive producer Sue Vertue.
Moffat aspires to tackle the details from the original stories that are rarely covered in adaptations, such as Watson marrying and living apart from Holmes. A part of the resolution to "The Reichenbach Fall" has been filmed.