Guy Ritchie’s “Sherlock Holmes” is Conan Doyle’s sleuth on steroids — literally. No longer the iconic brainiac, the new Holmes (Robert Downey Jr.) is just as much action hero as detective, with a penchant for flashy Hollywood displays of violence and explosions unimaginable to the original 19th century audience. True, Conan Doyle’s hero was capable of bending an iron poker with his bare hands (“The Adventure of the Speckled Band”), but who would have suspected that he was hiding such an impressive six-pack under all of that tweed? Or that he spent his free time in seedy fight clubs displaying a lot of muscle and an encyclopedic knowledge of how to rip apart the human body?

Counterintuitively, though the new Holmes has been madeover into an impressive physical force, he has also become a much deeper psychological character. Downey is lovably appealing as a raffish ruffian with a Captain Jack Sparrow-esque erraticism. Holmes is delightfully bizarre, verging upon the messed up. Genius, apparently, comes with its price; he swings between manic obsessiveness while working on a case, and deep depression while unemployed. He is unafraid of death, which is more an indifference toward life than courage. He has no friends except Watson (Jude Law), and even with him, he’s unable to show sincere emotion. Instead, they affectionately bicker and exchange witty repartee with so much British charm.

The dynamic duo brings a level of intelligence and nuance to an otherwise brutish orgy of bone-cracking, blood-splattering violence. Holmes is the eccentric genius with the body, and Watson 2.0 has also undergone a significant transformation. Usually portrayed as the fat, stupid sidekick, this Watson is none of the above. (It is Jude Law, after all.) He’s just as brave as Holmes, though a little less strong and a little less smart, and definitely much less crazy. Basically — he’s Holmes’s straightlaced pretty boy sidekick and his medical mind serves as the necessary sane counterpart to the former’s volatile nature.

The friendship between Holmes and Watson may in itself be enough of a reason to watch the film. And although Holmes and a spunky Irene Adler (Rachel McAdams) — an old flame — are matched, the romance runs thin. Her background and purpose are never entirely clear, and though perfectly charming, Rachel McAdams’ performance dims in comparison to her male counterparts; she provides a flash of female flounce in a skimpy red dress and a bit of color in an otherwise gritty, industrial London setting. But, sadly, the chemistry is simply nonexistent.

Yes, at times the currents between Holmes and Watson veer toward the homoerotic. What bromance doesn’t? They bicker like a little old married couple over who turned off the stove, or what kind of clothing is most flattering, and Holmes is clearly jealous of Watson’s budding romance with Mary (Kelly Reilly). After a particularly painful encounter when Holmes performs his detective magic on Mary, we are left with the realization that he is, in fact, painfully solitary in a life that offers little real pleasure or fulfillment.

Touching moments like these make the film a little more than just Ritchie’s specialty: flashy movies about badass guys that do a lot of cool stunts. If this seems a little at odds with the source material, it is, so if you’re a Sherlock Holmes by Arthur Conan Doyle purist, the strong taste of Hollywood might not be palatable. But even the diehard trekkies saw some merit in the 2009 remake of “Star Trek,” so sometimes Hollywood can get things right. Sherlock Holmes is soon to become its own enterprise, since the entire movie serves as an extended trailer for the inevitable sequel.