Ritchie's film sees the titular detective (Robert Downey Jr.) and his friend and partner Dr. John Watson (Jude Law) assist the police in arresting Lord Blackwood (Mark Strong) for a series of murders. However, when Blackwood appears to have risen from the grave after being hanged for his crimes, Holmes and Watson's investigations take a more sinister and supernatural turn.
It's clear from the very start that Ritchie's vision for his version of Conan Doyle's detective is quite far removed from the deerstalker wearing gent of past incarnations. Downey Jr. makes his Holmes an alluring and unconventional take on the character; whilst it never feels as though he quite fits the role as perfectly as he does Tony Stark in the Marvel Cinematic Universe, his performance in the role is compelling and strong throughout. Law also does well as Watson, again going against the stereotypical depiction of the character and instead playing things much closer to Conan Doyle's source material, focusing on Watson's status as a war veteran to generate the character's temperament and physicality. Whilst his turn is pleasing, Law is most entertaining when sharing the screen with Downey Jr., which thankfully for him takes in the vast majority of his scenes.
Elsewhere the casting is less successful. Rachel McAdams as Holmes' shady love interest Irene Adler never convinces, having neither the chemistry with Downey Jr. nor the presence on screen to make her character entertaining, mysterious or, at some points, necessary. Mark Strong is fine, but never receives enough screen time to make Lord Blackwood anything more than a scowling villain. Eddie Marsan also does well as Inspector Lestrade, but again the character just receives too little development to give the actor a chance to genuinely impress.
The film's plot, not taken directly from any of Conan Doyle's stories but instead inspired by elements from several of his works, engages well enough throughout, but suffers from a final act that can't quite live up to the mystery generated before it and a climax that underwhelms. The action elements throughout the film also jar too much with the detective story into which they have been placed. An underground bareknuckle fight Holmes takes part in early on in the film works well, revealing elements of the detective's character cleverly and enjoyably. Other sequences that see Holmes and Watson brawling with various baddies through Victorian London are uninspired, adding nothing to the story and feeling as though they are only there because director Ritchie doesn't know how else to link his film together.
Sherlock Holmes ends up, at least in part, as a wasted opportunity. There are several elements here that reboot the character and universe of Holmes incredibly well, led by a robust and compelling performance from Downey Jr. But there are also too many areas in which the film falls short or misfires to judge it as a true success. What we're left with is a good film that entertains well enough, but also feels as though it doesn't do enough with the ideas it has and the rich literary source material from which it takes inspiration. But there's enough here to launch the franchise, with future installments having the potential to remedy the less successful elements and create something genuinely pleasing.