 The synopsis for the episode reads " Sherlock has been gone for two years . But someone isn 't quite convinced that he 's dead . " The ' someone ' turns out to be Anderson , the forensics technician from series 1 and 2 ( who has now lost his job due to his obsessive conviction that the detective still lives ) . He had a long @-@ standing mistrust of Sherlock , yet is now one of the few people who believes Sherlock is alive , and throughout the episode is trying to convince Lestrade . Anderson tracks him via various mysterious events from Tibet to New Delhi to Germany in which he seems to be involved and points out that the incidents are getting progressively closer to London . 
