To be released tomorrow on DVD: "Sherlock Holmes"

Grade: B

Early in Sherlock Holmes - and also again, later on - the famous sleuth demonstrates his ratiocinative powers in a way undreamed of by his creater, Arthur Conan Doyle. Observing a thug standing guard over a horrible crime in a dimly lighted church, Holmes calculates just how to suprise the man, disarm him and beat him senseless. The viewer at home follows his thought process through slow-motion pre-enactment, observing how the laws of anatomy and physics will be used to snap bones, gouge organs and turn flesh into pulp. Then, having seen it diagramed once on screen, we see it all again, with more noise, in real time. Elementary!

Doyle's Holmes, who arrived in Victorian pop culture in 1887 (with the publication of A Study in Scarlet), has adapted since then to changes in taste and entertainment technology. He was a proto-superhero, amenable to all kinds of elaboration and variation, and even a measure of mockery, as long as the basics of the brand were respected. For most of his existence he has lived at 221B Baker Street, smoking a pipe, playing the violin and sticking faithfully to bachelorhood and his belief in the functional elegance of the deerstalker hat.

But Holmes has never been much for physical violence, and the chief innovation of this new, franchise-ready incarnation, directed by Guy Ritchie and played by Robert Downey Jr., is that he is, in addition to everything else, a brawling, head-butting, fist-in-the-gut, knee-in-the-groin action hero.

A smart one, for sure, and as played by Downey, with his characteristic twitchy-wit and haggard insouciance, he has more intelligence than the movie knows what to do with. (His Holmes has also lost the deerstalker, favoring battered porkpie - or bowlerlike headwear, perhaps in homage to Charlie Chaplin, another character Downey has played.)

Of course intelligence has never ranked high among either Ritchie's interests or his attributes as a filmmaker. His primary desire, most successfully realized early in his directing career, in Lock, Stock and Two Smoking Barrels and Snatch, has always been to be cool: to make cool movies about cool guys with cool stuff. Yes, Sherlock Holmes is kind of cool. But that's not really a compliment.

Still, it's getting close to Easter, and the teenage boys in the house have fructose in their bloodstreams and time on their hands, so let's call it half a compliment. There are worse things than loutish, laddish cool, and as a series of poses and stunts, Sherlock Holmes is intermittently diverting.

The visual style - a smoky, greasy, steam-punk rendering of Victorian London, full of soot and guts and bad teeth and period clothes - shows some undeniable flair. And so do the kinetic chases and scrapes that lead us through the city, as Holmes and his pal Watson (Jude Law) scramble to unravel a conspiracy so diabolical that it fails to be interesting. Best of all is the banter between Downey and Law, who is looser and more mischievous than he's allowed himself to be in quite some time. The mustache suits him.

Speaking of which: the beard is Rachel McAdams. She is inserted into the picture in a pretty, flouncy red dress to add a splash of color and dispel a few hints of homoerotic subtext. Holmes and Watson are longtime roommates, with an Oscar-and-Felix routine of quarrelsome affection. Watson's engagement to a page of half-written dialogue named Mary (Kelly Reilly) sends Holmes into a snit of jealousy, which loses some of its interesting implications when McAdams shows up as a luscious thief named Irene Adler. I wonder: is she the ancestor of Jake and Jane Adler, the main characters of It's Complicated? Or does a DVD coming out around this time need to have a character named Adler in it for some reason?

McAdams, in any case, is a perfectly charming actress and performs gamely as the third wheel of this action-bromance tricycle. But Irene, though she figures in a few of Conan Doyle's stories, feels in this movie more like a somewhat cynical commercial contrivance. She offers a little something for the ladies - who, according to airtight Hollywood corporate logic, are more likely to rent a movie like this one if there's a feisty woman in it - and also something for the lads, who, much as they may dig fights and explosions and guns and chases, also like girls.

Just like Holmes and Watson! They really do, in spite of the barely sublimated physical passion they manifest for each other in nearly every scene. I'm sure Amazon, Movie Trading Company, Netflix, Blockbuster et al would like me to change the subject and tell you about the amazing diabolical conspiracy that tests Holmes's ingenuity, along with his faith in the supremacy of reason.

It seems that an evil aristocrat (Mark Strong), executed for a series of murders, returns from the dead to mobilize an ancient secret society that he may have time-traveled into a Dan Brown novel to learn about. Doesn't that sound fascinating? I thought not. But there will be a sequel, for which this frantic, harmless movie serves as an extended teaser, and it looks as if it might feature Holmes's literary archnemesis, Professor Moriarty. No doubt Holmes will break a chair over Moriarty's head, kidney-punch him and kick him in the face. Wittily, though, like the great detective he is.