Cracking the case of Sherlock's enduring longevity

Both myself as writer-creator-EP of Sherlock & Daughter, and showrunner James Duff, fell in love with the Holmes stories as kids. They were very popular for me growing up in Belfast in the 1970s, even as the place was going to hell in a handbasket during the Troubles.

Maybe it was the stability of Holmes’ eternal fog-filled imaginary version of Victorian London that appealed, with Baker Street at its heart. James, brought up in rural Texas, and myself in Northern Ireland, devoured Arthur Conan Doyle’s stories at an early age and both recognised how important the sense of time and place in late Victorian London was to our story.

Conan Doyle described himself as “An Irishman by extraction… though born in Edinburgh, where two separate lines of Irish wanderers came together under one roof”.

I thought about that years later, when we were filming Sherlock & Daughter on the streets of Dublin, where many locations now look more like Victorian London than London does.

Sherlock’s public embrace

Around 2019, as the very last of the detective’s stories were falling out of copyright into the public domain, a flurry of adaptations and spin-offs in print, TV and cinema were recruiting a new generation to Holmes’ army of devoted readers.

Personally, I think the escape of Holmes and Watson into the public domain, presumably via a perilous window in Baker Street, is not the main reason for their modern popularity. It certainly didn’t hurt, but Holmes was already – according to the Guinness World Records – the most portrayed literary character in TV and cinematic history, with over 25,000 depictions on screen and in print.

That is around the time I started thinking about the idea that became Sherlock & Daughter. In short it was the vexed question of what made Sherlock, Sherlock?

Was he born like a giant brain in the glass jar of some mad Victorian scientist, all intellect and very little emotion? Or were there perhaps events that helped shape his character and his famous aversion to passion in general and romance in particular.

Rather than tread the well-beaten path of a youthful origin story, I thought it would be more fun to confront the great detective with an origin story unfolding in his later years, with Holmes as a lion in winter, forced to confront the choices of his formative years.

We also felt a younger adult audience would find a way into the stories alongside a more mature one, not by changing Sherlock Holmes, but by adding a combustible ingredient.

Was he born like a giant brain in the glass jar of some mad Victorian scientist, all intellect and very little emotion? Or were there perhaps events that helped shape his character and his famous aversion to passion in general and romance in particular - Brendan Foley

Amelia, a young woman, shows up on the doorstep of 221B Baker Street, claiming that she is Sherlock Holmes’ illegitimate offspring.

To add to the shock, she is American. Going even further, she is an interesting mix of Anglo, native American and Hispanic heritage. Amelia, constantly at war with her mentor and possible father, is wonderfully portrayed by a young actor Blu Hunt, herself with a similarly diverse heritage, including Native American.

Generation games

Our producers, Starlings and StoryFirst, were blessed to find broadcasters in The CW in the US, Warner Bros Discovery in the UK/Ireland, and SBS in Australia along with many of the Nordic public channels, who loved the interplay of two generations both onscreen and in the audience.

Holmes and his alleged daughter set off to solve a twisty series of crimes together while interrogating their own possible familial connection. That gave me, James and our fellow writers Shelly Goldstein and Micah War Dog Wright the rocket fuel for a very modern-feeling series, while being totally respectful not just to the original characters, but to the period and world of their story.

The question of whether the frosty Mr Holmes would ever risk even a single youthful fling keeps us on our toes through the whole series. Holmes fans sometimes cite the character Irene Adler, a particularly clever opera singer who appears in a single Holmes story – A Scandal in Bohemia – as the nearest he gets to romance, but in truth he is in love with her brain.

In the words of Watson: “It was not that [Holmes] felt any emotion akin to love for Irene Adler. All emotions, and that one particularly, were abhorrent to his cold, precise but admirably balanced mind.”

‘The industrialisation of crime’

Outside the lineage storyline, our theme for the series is the changing era at the turn of the 19th century: when science and invention are joining banking and industry to crowd out a previous age of individualism.

Our Holmes is witnessing what he calls “the industrialisation of crime” at a time where bank robbers are replaced by robbers in banks, and even villains like Professor Moriarty are being edged out by syndicates and late Victorian new technology.

We called the shadowy international criminal enterprise in our story The Red Thread, a homage to Holmes’ own description in his first story, A Study in Scarlet: “There’s the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it.”

Remaining faithful to classic characters and setting while adding a passionate, youthful voice – bringing heart to Holmes’ head – is also helped attract our great cast.

Like the writers, David Thewlis was a huge Holmes fan to begin with, incredibly well-read through the canon. David cites the scripts and the intriguing possible father-daughter relationship as key to his deciding to make the series, adding his own version of Holmes to the repertoire.

He is one of the best-prepared actors I have ever worked with, knowing most of his lines for the entire series even before the first read-through. This caused a domino effect with the other talented younger actors bringing their A game, which – hopefully – results in something special.

His range offered intangible benefits too.

One day during filming in Dublin, when David left a great Victorian doorway to stride the straw-strewn streets to an awaiting carriage, a passing family of spectators, all awe-struck, were divided.

“That’s David Thewlis from Fargo,” one of the parents whispered. “No, it’s not,” said one of their teen offspring. “That’s Remus Lupin from Harry Potter,” before both agreed: “Oooh. Sherlock Holmes!”.

• Brendan Foley is an award-winning screenwriter whose credits include Viaplay crime drama Cold Courage