Peter Harness and Guy Ritchie’s latest spin on Sherlock Holmes, titled Young Sherlock, has surprised audiences by completely deviating from Sir Arthur Conan Doyle’s works regarding Jim Moriarty’s origins. With the cynical genius encountering Holmes as a friend rather than his arch-nemesis in the Prime Video series, portrayer Dónal Finn has explained why the creators decided to adopt such a massive change.
Dónal Finn explains why Young Sherlock changed Moriarty’s origin story
During a recent conversation, the Irish actor noted that by revamping Moriarty’s backstory, the Young Sherlock creators wanted to surprise viewers, all the while maintaining the essence of the villainous character.
“It was so much fun to subvert that idea of what the audience is maybe anticipating when they hear about someone playing Moriarty, while still serving what I think is true to his character, even later in life, in Doyle’s books,” Dónal Finn told Comic Book Resources. “So many people will [watch] the show knowing the lore of Sherlock and, in the introduction to Moriarty, will understand who he is now and who he will be.”
The Wheel of Time star then specified that the two characters having “great appreciation and admiration for each other” would help deepen “any kind of sense of betrayal or heartache once they have to divide.”
Expanding upon Moriarty’s origins in Young Sherlock, Finn noted, “He probably had a hard life growing up, and then he had to fight to get to Oxford. As an Irish person at that time, that was a great achievement. Then, it’s just an unfortunate set of circumstances. He probably had things happen to him that meant he had to see the world in a different way. He probably learned that the world is unfair. Once he had learned that, he said, ‘If that’s the case, why should I fight fair?'”
Additionally, Dónal Finn shared, “I don’t think that makes him a fundamentally bad person, but I think it shows why Moriarty’s moral compass is slightly askew [compared] to [Sherlock’s], and Moriarty doesn’t believe one is better than the other. It’s just different.”
Also featuring Hero Fiennes Tiffin, Young Sherlock dropped all eight episodes on Prime Video on March 4, 2026.
Originally reported by Apoorv Rastogi on ComingSoon.net.
