In the final episode of this new series, written by Mark Gatiss and Steven Moffat, long buried secrets finally catch up with the Baker Street duo.

Someone has been playing a very long game indeed and Sherlock and John Watson face their greatest ever challenge. Is the game finally over?

Benedict Cumberbatch returns as Sherlock Holmes, with Martin Freeman as John Watson, Mark Gatiss as Mycroft, Rupert Graves as Inspector Lestrade, Una Stubbs as Mrs Hudson, Amanda Abbington as Mary Watson, Louise Brealey as Molly Hooper.

With thanks to BBC Media.