(M) ****

Director: Guy Ritchie.

Cast: Robert Downey Jr, Jude Law, Jared Harris, Noomi Rapace, Stephen Fry, Rachel McAdams.

GUY Ritchie's robust re-imagining of Sherlock Holmes may have upset some who can't bear the thought of the famed detective being involved in fistfights and explosions and without his iconic deerstalker.

But these adaptations - while playing loose with Sir Arthur Conan Doyle's plots - remain surprisingly faithful to the character, who was known at times to use martial arts, carry a pistol and be a bit bohemian.

Source fidelity aside, the thing that really matters is that Ritchie's re-interpretation is exciting, witty and great fun.

Inspired by Doyle's The Final Problem, A Game Of Shadows sees Holmes (Downey Jr) square off against arch-nemesis Professor Moriarty (Harris), whom Holmes believes is connected to a series of murders and terrorist acts.

Holmes' pairing with Dr Watson (Law) has ended due to Watson's impending nuptials, but Holmes is forced to bring his old partner back into the fold to protect him from Moriarty. Soon the two are racing around Europe, trying to keep up with Moriarty and prevent him from starting a war.

A criticism often levelled at Ritchie is that he is style-over-substance, but A Game Of Shadows (and its predecessor for that matter) is a nice marriage of the two. Ritchie's use of slow motion, zippy editing, and flash-forwards never get in the way of an intelligent plot, a witty script, and great performances.

Downey Jr breezes his way through the role of Holmes - it's an easy, yet comfortable role for him - and Law makes for a great foil, with their back-and-forths and chemistry a highlight. And as good as the lead pair are, Fry almost steals the show as Sherlock's brother Mycroft, particularly in one eye-opening scene that reveals more of Fry than you've likely ever seen before. Rapace, so impressive in the Swedish original of The Girl With The Dragon Tattoo, is slightly wasted as the gypsy Simza, while Harris underplays Moriarty, thankfully restraining himself from the opportunity to twirl his moustache in villianish caricature.

While still set near the turn of the century, some of the film's plot devices push the bounds of belief and the almost steam-punk-ish look of the movie will put some people off.

But this is a great piece of mystery-fuelled fun that plays to Ritchie's strengths and is as smart as it is enjoyable.