Series 4 Trailer #2 | Sherlock

“You know why I’m here” Here's a brand new trailer for #Sherlock series 4... Viewers in the UK can watch Sherlock on BBC iPlayer: https://bbc.in/4glzR9d Subscribe here for more Sherlock:    / @sherlock221b   Sherlock YouTube Channel    / @sherlock221b   Sherlock Facebook:   / sherlock.bbcw   Sherlock Twitter   / sherlock221b   This is a commercial channel from BBC Studios. Service & Feedback https://www.bbcstudios.com/contact/co...