7 Reasons Sherlock Series 4 Should Be The Last

Rumours abound that the fourth series of 'Sherlock' will introduce the third Holmes brother - Sherrinford - who may or probably won't be played by fellow Marvelista Tom Hiddleston. Thing is ...Sherrinford doesn't exist in the original Holmes canon (as in, penned by Sir Arthur Conan Doyle) nor was the existence of a mysterious third sibling even hinted at.

The eldest sibling was postulated by 'Sherlock Holmes' scholar (a fancy title for "Cumberbitch") William S. Baring-Gould. He suggested that, since the Holmes dynasty has means, an eldest son must be off looking after the family estate. Since Mycroft was busy representing the British government, that duty must have fallen to another. Sherrinford, or a mysterious Holmes brother of some sort, has since appeared in numerous Holmes stories by other authors.

Unlike a lot of early onscreen Holmes adventures, the creative team behind 'Sherlock' have always drawn from the original Conan Doyle stories for their main inspiration, though they often play fast-and-loose with it. There's nothing wrong with plundering a century's worth of Holmes adaptations for inspiration, but if Sherrinford is their best move then it suggests they've run out of things to draw on for the series.

If that's the case, they should take the time to develop an original idea, craft a 90 minute special from it and come back strong in a few years. The New Year's Day special 'The Abominable Bride' was an almost entirely original idea, extrapolated from a throwaway reference to a past adventure by Watson in 'The Adventure of the Musgrave Ritual'. Despite the mixed critical reception, 'The Abominable Bride' proved new ideas and holiday specials can work for 'Sherlock'.