Archenemies. Bitter Rivals. Lifelong friends? The relationship between legendary detective Sherlock Holmes and his supreme rival James Moriarty is the stuff of legend. Over the decades (and centuries) the dynamic between the two characters has served as the focal point of countless literary and on-screen adaptations. They’re the embodiment of good and evil. Holmes is moral and just; Moriarty cold and calculating. But the new streaming series Young Sherlock, premiering March 4 on Prime Video, puts a new twist on the classic rivalry.
Debuting at IGN Fan Fest 2026, a brand-new exclusive clip – which you can watch in the player above – shows the moment Sherlock Holmes meets his future adversary. And if the scene doesn’t scream “soon to be foes,” that was by design. I sat down with series star Hero Fiennes Tiffin (Harry Potter, The Ministry of Ungentlemanly Warfare), who plays Sherlock, to talk about his character’s relationship with Moriarty, working with Guy Ritchie, and what kind of Sherlock video game he’d like to see.
“Sherlock always needs a counterpart,” Tiffin says. “It is usually Watson. And in our story, having it be Moriarty, you realize they learn so much from each other. Enemies who used to be friends, that’s just a fascinating thing to explore. So it is fun watching, knowing that this plane is going to crash and burn. They have slightly different approaches, but they still have loads of similarities and they make a great team. Butch and Sundance was a reference that our showrunner used a lot.
“I did some chemistry reads with people auditioning for Moriarty. We met with loads of people and everyone was really, really exceptional. And Dónal Finn (who plays Moriarty) came in and I think about five seconds into his first line, I was like, ‘This guy is going to make me look bad if I’m not careful.’ He is a sensational actor. We have very different approaches to acting. He’s theater trained, and I’ve only done screen acting. We worked a lot of scenes in prep, making sure that we kind of finish each other’s sentences or we sip our drink at the same time, stand up at the same time, sit down at the same time. And there are a few little moments where we try to create some kind of nuanced indications of their synchronicity because they are a great team.”
In the series, Sherlock Holmes is far from the detached and analytical detective we’ve come to know. As portrayed by Tiffin, he’s young, inexperienced, and somewhat cheeky. Tiffin says that while he wanted to make the character his own, he was definitely inspired by the renowned actors who’ve played Holmes on screen.
“Just being a fan I subconsciously digested a lot of Sherlock,” Tiffin says. “Specifically Benedict Cumberbatch and Robert Downey Jr.’s portrayals. But when I got the role, I’d already watched the films two or three times, so I didn’t want to directly watch (them) again and draw inspiration and make notes. I felt like I’d, in quite a healthy general sense, digested what I needed to before getting the role. So when it came to preparing for the role of Young Sherlock, it was prep directly correlating to the script.”
Given the almost superhuman abilities of Sherlock Holmes, it’s easy to consider the character among the ranks of quick-witted superheroes like Batman, Black Panther, and Iron Man. Tiffin says he took inspiration from those characters as well.
“it’s something that I’ve thought about a lot,” Tiffin says. “When I think about why people gravitate towards this character, I think it’s because he is as close to being a supernatural character who isn’t a supernatural character. He’s as close to being beyond human in his capabilities. He’s just skin and bone the rest of us, but just an exceptional intellectual person. He’s close to being (a superhero), but he’s not. And I think that’s what makes him so alluring and intriguing.”
Guy Ritchie, who directed Downey Jr. in two Sherlock Holmes movies, serves as Executive Producer of Young Sherlock. Tiffin, who had a role in Ritchie 2024’s film The Ministry of Ungentlemanly Warfare, says working on Young Sherlock was the quintessential Guy Ritchie experience.
“When I worked on The Ministry of Gentlemanly Warfare,” Tiffin says, “Henry Cavill had three pages (of the script) delivered to him about 20 minutes before shooting. There were about four other actors (who) have no lines in response. We are just watching and listening, and we were all thinking ‘better him than me.’ (With Young Sherlock) it became my turn. There’s a scene at a party (where) Guy gave me a good two or three pages of dialogue with less than half an hour to learn, and it was terrifying. But if he gave you the option to just read the lines that you’ve learned the night before, you would always pick his. You’re in good hands. He’s asking a lot of you (but) he helps facilitate by knowing how he’s going to edit it. So even if you feel like your acting might take a hit, you’d still want to do that. That’s the biggest challenge with Guy: when he hands you dialogue last minute. But it’s always for the best.”
Tiffin, who at times has been a big fan of Call of Duty and FIFA games, says he’d love to see his version of Sherlock Holmes adapted as a video game at some point.
“Maybe (like an) early Uncharted game,” Tiffin says. “You’ve got a mix of action, but you’re also kind of puzzle solving. (Maybe) early Prince of Persia, the platform versions. I think there would have to be a lot of problem solving, I guess story mode. (A) single player combination of fighting and problem solving. I’d buy it, I’d play it.”
Young Sherlock streams March 4 on Prime Video.
Michael Peyton is the Senior Editorial Director of Events & Entertainment at IGN, leading entertainment content and coverage of tentpole events including IGN Live, San Diego Comic Con, gamescom, and IGN Fan Fest. He’s spent 20 years working in the games and entertainment industry, and his adventures have taken him everywhere from the Oscars to Japan to Buenos Aires, Argentina. Follow him on Bluesky @MichaelPeyton
