'Young Sherlock' season 2 recasts key character as Amazon series begins new chapter

Dónal Finn is departing and Freddie Fox is stepping in to play James Moriarty

Amazon Prime Video's Young Sherlock is making a major casting change for its second season, with actor Dónal Finn departing the series and Freddie Fox stepping into the role of Sherlock Holmes' future nemesis, James Moriarty. The shake-up comes as production gets underway on the next chapter of the hit mystery drama.

According to CBR, Fox will replace Finn as Moriarty after the character's dramatic introduction in the first season. While Amazon has not explained the reason for the recasting, the change marks one of the biggest behind-the-scenes developments since the series was renewed earlier this year.

Hero Fiennes Tiffin will return as the young Sherlock Holmes, alongside Zine Tseng as Princess Gulun Shou'an, Joseph Fiennes as Sherlock's father Silas Holmes, Natascha McElhone as Cordelia Holmes, Max Irons as Mycroft Holmes and Colin Firth as Sir Bucephalus Hodge. Guy Ritchie is also back to direct the opening episode of the new season.

Freddie Fox is best known for roles in The Crown, The Gentlemen, House of the Dragon and Slow Horses. His casting suggests season 2 will place an even greater emphasis on the rivalry between Sherlock and Moriarty as the detective continues to develop into the legendary sleuth created by Sir Arthur Conan Doyle.

Inspired by Andrew Lane's Young Sherlock Holmes novels, the series follows a 19-year-old Sherlock at Oxford University as he investigates his first murder case, uncovering a conspiracy that will shape his future. Young Sherlock was renewed for a second season by Prime Video in April following a successful debut, with production now underway.