The Six Thatchers
S04E01 - Airdate: 2017-01-01
Runtime: 90 min
While waiting for Moriarty to make good on his beyond-the-grave threat, Sherlock is intrigued by cases of vandalism where the criminal is breaking open busts of Margaret Thatcher. He soon discovers that the vandalism is tied to Mary's past.
Episode details and rating from TVmaze.