In this eagerly anticipated fourth series, Sherlock is back on British soil once more, while Doctor Watson and Mary prepare for their biggest ever challenge – becoming parents for the first time. The hit drama returns with three new episodes promising laughter, tears, shocks, surprises and extraordinary cases. SDH

Episodes

The Six Thatchers

Sherlock waits to see where Moriarty will make his posthumous move. One mysterious case in particular baffles Scotland Yard, but Sherlock is more interested in a seemingly trivial detail. Why is someone destroying images of the late prime minister Margaret Thatcher? Is there a madman on the loose? Or is there a much darker purpose at work? Something with its roots deep in Mary Watson's past...