Sherlock is a global TV phenomenon, sold in over 240 territories worldwide and the winner of 12 Baftas and seven Emmys. It's the BBC's top-rated drama in the UK for more than a decade, and the last season was watched over 100 million times in China alone. 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.