Participants followed clues by tracing a path across linked posts and accounts that ultimately promoted the season finale

On January 10th, 2017 at 8pm GMT, a message went out on Twitter:

This was the beginning of an interactive mystery hosted by BBC One to promote the Sherlock season finale. Using Twitter to engage the audience in testing their crime solving skills and dubbed the “world's biggest live mind game“, #SherlockLive had all the makings of a whodunnit drama. Written in the tone of Sherlock's biting wit, there were taunts, calls for deductions, and multi-media clues throughout the experience.

Fan reaction was extremely positive, with comments ranging from “amazing” to “confusing” (the confusing is actually a good thing in Sherlock land). The mystery was written by Torchwood and The Sarah Jane Adventures veteran Joe Lidster, with Steven Moffat and Mark Gatiss manning the Twitter feed.

BBC One

On January 10th, 2017 at 8pm GMT, a message went out on Twitter:

We have received a text from someone claiming to be Sherlock Holmes. We won’t let this happen. #SherlockLive #NotGonnaHappen pic.twitter.com/lCJGctPAhc

— BBC One (@BBCOne) January 10, 2017

This was the beginning of an interactive mystery hosted by BBC One to promote the Sherlock season finale. Using Twitter to engage the audience in testing their crime solving skills and dubbed the “world's biggest live mind game“, #SherlockLive had all the makings of a whodunnit drama. Written in the tone of Sherlock's biting wit, there were taunts, calls for deductions, and multi-media clues throughout the experience.