Young Sherlock Review: Guy Ritchie Reinvents Holmes With Swagger as Hero Fiennes Tiffin Ignites the Origin Story

Guy Ritchie ignites Baker Street with Young Sherlock, a kinetic origin story fronted by Hero Fiennes Tiffin and powered by Joseph Fiennes, Natascha McElhone, and Colin Firth—a slick, swaggering reinvention of the legendary detective for a new generation.

Guy Ritchie is back in Holmes country, but not the way you probably expect. His new show digs into Sherlock’s misspent youth, swaps Watson for Moriarty, and turns the origin story into a sleek, eight-episode conspiracy ride. It is not an extension of the Robert Downey Jr. movies; it is its own beast, and a fun one.

What this Young Sherlock actually is

Drawn from the idea space of Andrew Lane’s YA novels but charting its own course, this series plants Sherlock in his teens-to-early-20s window and asks: what if his first big case didn’t make him famous — it almost ruined his life? Showrunner Matthew Parkhill leans into that premise and builds a version of Holmes who is brilliant, unpolished, and wildly entertaining. Think early-days mythmaking in the way certain galaxy-far-far-away prequels reframed a hero and a villain we thought we knew.

The setup

At 19, Sherlock (Hero Fiennes Tiffin) has the brains, the nerve, and a knack for petty trouble. After one scrape too many, his older brother Mycroft (Max Irons) hauls him out of it and ships him to Oxford to rebuild his reputation. There, Sherlock meets the dazzling James Moriarty (Donal Finn), and the two click in that dangerous way only razor-sharp minds do.

Oxford is buzzing: Sir Bucephalus Hodge (Colin Firth) is unveiling a gleaming new science building, and visiting dignitary Princess Gulun Shou-an (Zine Tseng) is on campus. Then a prized artifact vanishes, a body drops, and Sherlock finds himself under suspicion. He and Moriarty team up to clear his name, pulling a thread that leads out of England, through a globe-spanning conspiracy, and straight back into Sherlock’s own past. The season tells one big story across eight chapters, each episode adding a new wrinkle just when you think you’ve got it pinned.

The players

• Hero Fiennes Tiffin as Sherlock Holmes — cocksure, brilliant, not yet house-trained as a detective; flashes of a mind-palace style and a reckless streak that feels earned
• Donal Finn as James Moriarty — magnetic, quick, and a true equal; the best on-screen Moriarty vibe since Andrew Scott
• Max Irons as Mycroft — exasperated, strategic, the family fixer
• Natascha McElhone as Cordelia Holmes — Sherlock’s mother, adding texture you don’t usually get in Holmes stories
• Joseph Fiennes as Silas Holmes — Sherlock’s father; he and Tiffin share a couple of charged scenes that do real character work
• A sister named Beatrice expands the Holmes clan nicely
• A young constable Lestrade pops up, planting seeds for the future
• Colin Firth as Sir Bucephalus Hodge — pompous in all the right ways; not a cameo-for-cameo’s-sake, and crucial to the plot
• Zine Tseng as Princess Gulun Shou-an — a sharp romantic and intellectual foil; you may know her from 3 Body Problem

How it plays

Tiffin’s take is a smart composite without feeling derivative: flashes of mind-palace deduction, a dose of Jonny Lee Miller’s impulsivity, and none of the hyper-stylized brawling of the Downey films. He’s brilliant and breakable — which makes him fun to watch. The show’s ace in the hole is pairing Sherlock with Moriarty as friends and partners before the schism that will define them. Tiffin and Finn spark, bluff, and outmaneuver each other in ways that tease classic Holmes iconography without winking it to death.

The family angle works too. Seeing Sherlock bounce off his mother, father, and sister gives you a clearer sense of how this particular mind got built. Colin Firth chews just the right amount as Hodge, and Joseph Fiennes’ limited screen time still lands. Zine Tseng is a standout — the rare character who can pull focus from Sherlock and keep it.

Structurally, it is a clean season-long case with episode-by-episode payoffs. Every chapter introduces a new problem or revelation that reframes the last, and the show hops beyond Victorian London often enough to feel big without losing its core mystery engine.

Direction and style

Guy Ritchie executive produces and directs the first two episodes, then hands the reins to Anders Engstrom for three and to Dennie Gordon and Tricia Brock for the rest. Ritchie’s touch is present but dialed-in — you’ll catch a bit of stuttered editing, a slow-motion flourish, and some sly anachronistic music choices — yet the overall look is more restrained than his Sherlock movies and even more subdued than his recent TV work on The Gentlemen. It feels like a filmmaker who knows when to goose the pulse and when to let actors and character work carry the frame. As a bonus bit of trivia, Ritchie reunites here with Tiffin after The Ministry of Ungentlemanly Warfare.

The bigger swing

Centering the early Holmes-Moriarty relationship instead of rushing to Watson is a bold bet, and it pays off. By the end, you can see a clear runway — roughly a decade of story time — before we reach the fully-formed Baker Street legend. The game is very much on, and there is plenty of room for more adventures.

Bottom line

Young Sherlock is a lively, confident reinvention: new continuity, classic flavor, strong chemistry at its core. It is the most purely enjoyable spin on the character in a while.

Young Sherlock premieres March 4 on Prime Video.