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The Final Problem

Series 4 - Episode 3 The Final Problem



After the previous episode's sensational plot twist – spoiler warning, but yes, Benedict Cumberbatch’s Sherlock and brother Mycroft have a sister – you’ll be asking yourself one thing: has the sinister sibling also shot Martin Freeman’s John Watson, who had just cottoned on to the fact that she was both his flirty admirer on the bus and his therapist?

Played by Sian Brooke, her intent (ill or otherwise) will be revealed tonight, as will the riddle of who or what “Sherrinford” is, and why the BBC has been teasing us with those images of a flood ruining the carpet at 221B Baker Street.

Oh, and expect to see Andrew Scott’s Moriarty pop up too, as part of an episode that we must savour for all it’s worth. Despite the demands on the cast, the production team is keen to make more Sherlock (this epidode's title The Final Problem notwithstanding…) but we’ll probably have to wait at least a couple of years to see it.


The sleuth and Watson face their greatest challenge as the duo's long-buried secrets come to light and a threat from the past seems to have returned from the dead. They discover an elusive enemy has been playing a very long game - which is now reaching its devastating conclusion. Benedict Cumberbatch and Martin Freeman star in the conclusion of the fourth series of the detective drama. Last in the series.

Cast & Crew

Sherlock Holmes Benedict Cumberbatch
Dr John Watson Martin Freeman
Mrs Hudson Una Stubbs
Molly Hooper Louise Brealey
Mycroft Holmes Mark Gatiss
DI Lestrade Rupert Graves
Mary Watson Amanda Abbington
Director Benjamin Caron
Executive Producer Steven Moffat
Executive Producer Mark Gatiss
Producer Sue Vertue
Writer Steven Moffat
Writer Mark Gatiss
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