Sherlock Holmes’ fame and appeal began because of, and fundamentally remains sustained by, the popularity and readability of the stories written by his creator, Sir Arthur Conan Doyle.

Which makes it all the more odd that, when it comes to cinematic outings for Holmes and his chum Watson, so few of Doyle’s stories are, ‘The Hound of the Baskervilles’ being a very obvious exception, considered to be worth adapting.

Holmes films seem to be content to dance in the margins around Doyle’s own work. They’re reinterpretations, origin stories, comedies, re-writings of or ‘takes on’ an idea of Sherlock Holmes that exists in the cultural supercontext. They’re re-workings of Holmes as he exists in the popular imagination, not as he appears on the pages of Penguin Classics.

Guy Ritchie’s film is no exception to this very general rule.

It’s ‘Sherlock Holmes as contemporary action movie’ and the clichéd plot structure and even more clichéd visual style are designed to drive this simple idea forward.

This is basically ‘Sherlock Holmes and the Weapon of Mass Destruction’. This means we get an action finale in the final reel, and plenty of punch ups along the way, while at no point does Ritchie pass up an opportunity for a bit of ersatz bullet time, some discontinuous editing or a sudden sharp cut.

Ritchie has made some of the very worst major releases of the last ten years, and shows no sign at all of becoming a more interesting, expressive or even capable director here.

When the film works (which is, to be fair, a surprisingly large amount of the time) it is because of one of two things. Firstly, the inherent strength of the Holmes character (rather than anything that is being done with, or to, him by the film itself) and secondly the performance of Robert Downey Jr as said character.

RDJ is a brilliant actor. He is, in fact, one of the finest living American actors. Here he turns in a compulsive, theatrical, exactly-the-right-side-of-ludicrous performance that is so far over and above the call of duty it’s in the same company as Miranda Richardson in ‘Damage’ or Will Smith in ‘Ali’. RDJ is screamingly over the top while being entirely convincing. Very obviously barking mad while convincingly the (second) greatest and most logic deductive mind in the British Empire.

He’s accompanied, for the most part, by Jude Law’s serviceable, laconic Watson, of whom the best that can be said is that he’s more believably an actual real live human than most of Law’s other screen roles and at least the Americans like him.

‘Sherlock Holmes’ is, when not being actively disabled by a score from Hans Zimmer so shamefully clichéd and inappropriate that you wish they’d take his Oscars off him, enjoyable, kinetic nonsense that doesn’t outstay its welcome.

I’m not sure that Ritchie’s reductive version of Holmes is worth another outing, but I’d love to see RDJ in the part again. If someone were to announce that, for the projected sequel, they’re sacking everyone apart from the leading men, it would instantly become a much more appealing prospect.