Fiona Shaw has joined the new Sherlock Holmes film franchise.

Fiona Shaw

Fiona Shaw

The 60-year-old actress is set to star alongside Millie Bobby Brown and Henry Cavill in a host of movies based on Nancy Springer's young adult fiction book series 'The Enola Holmes Mysteries' with Harry Bradbeer at the helm.

'The Enola Holmes Mysteries' tells the story of the titular teenage sister (Brown) of Sherlock Holmes (Cavill) and Mycroft Holmes who is also a detective.

There are no details yet on who Shaw will play.

Jack Thorne has penned the script for the new film and Helena Bonham Carter has also joined the cast as Enola's mother.

There are a total of six novels in the series, 'The Case of the Missing Marquess', 'The Case of the Left-Handed Lady', 'The Case of the Bizarre Bouquets', 'The Case of the Peculiar Pink Fan', 'The Case of the Cryptic Crinoline' and 'The Case of the Gypsy Goodbye'.

Brown, 13, developed a relationship with Legendary Entertainment after recently making her big screen debut as Madison Russell in 'Godzilla: King of the Monsters'.

Legendary are producing with Brown and her sister Paige Brown via the duo's PCMA Productions shingle.

Shaw recently appeared in Phoebe Waller-Bridge's BAFTA-winning spy thriller series 'Killing Eve' as the head of the Russia Section at MI6, Carolyn Martens, alongside Jodie Comer as psychopathic assassin Villanelle and Sandra Oh as agent Eve Polastri.

Shaw recently credited the hit show's success to having three strong female leads who don't rely on their "husbands or sons" while admitting it was refreshing not to play a moralistic character.

She said: "We've all been brought up on endless boys doing this work and enjoying them, so it's fantastic to have three people who are female running the good and bad of this world.

"It's a joy not to play plain virtue. Women often play virtue and it's very nice to not necessarily be good, and not necessarily be bad. The three women are not tied to a home or to husbands or sons."

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