Robert Downey Jr., near left, and Jude Law star as a more muscular Holmes and Watson. / ALEX BAILEY

LONDON - In a filthy, dank labyrinth of rooms below the streets of the East End, Sherlock Holmes was solving a case. That is, Robert Downey Jr., playing Holmes in the forthcoming film“Sherlock Holmes,”was engaged in hand-to-hand, foot-tostomach combat with a very big and very bad villain (Robert Maillet). Bam! Pow! Ouch! Both characters would end up knocked out on the floor, along with Holmes’s trusty sidekick, Dr.John Watson, played by Jude Law.


Filmed in December, the scene presented a sharp corrective to the popular cinematic view of Holmes, at least the one propagated by the old films featuring the wonderfully named British actor Basil Rathbone. Rathbone’s Holmes occasionally wielded guns, leapt out of carriages and rushed through the fog with Errol Flynn-style panache, but mostly he was a giant brain inside a tweed suit, sexlessly debonair in the way Hollywood liked its leading men in the 1930s and 1940s. His Watson, played by Nigel Bruce, was a good-natured, simpleminded foil for Holmes’s brittle brilliance.


The Sherlock Holmes of“Sherlock Holmes,”which is scheduled for release next fall, will still be smarter than everyone within a three-planet radius, and he will retain his uncanny ability to intuit whole life stories from the tiniest speck of dust on a shoe. But he will do those things while being a man of action?“like James Bond in 1891,”Joel Silver, one of the film’s producers, said last fall.


Lionel Wigram, who conceived the story and is also a producer of the film, said that reinventing Holmes as an action hero made perfect sense.“I never agreed with the idea of the fairly stuffy Edwardiantype gentleman,”Mr. Wigram said.“It wasn’t my idea of Sherlock Holmes.”


The director, Guy Ritchie? formerly Madonna’s husband? is known for stylized, quick-talking, fast-moving films set among the criminals, lowlifes and hard men of London’s underworld. He would seem to be a gamble as director of such a big Hollywood extravaganza.


The“Sherlock Holmes”producers say that Mr.Ritchie’s style is perfectly suited to their concept.“We thought he had the capacity and the ability to make a big, fun movie, and what really pushed it over the top was Robert Downey Jr.,”Mr.Silver said.


Mr.Downey’s Holmes is darker than that of Mr.Rathbone or others who have taken on the part, like Christopher Plummer in“Murder by Decree”(1979) and Nicol Williamson in“The Seven-Per- Cent Solution”(1976).The new Holmes is rougher, more emotionally multilayered, more inclined to run with his clothing askew, covered in bruises and smudges of dirt and blood.


Character and actor share certain traits. Like Holmes with his cocaine habit, Mr.Downey has been buffeted by many internal vicissitudes, including a long spell of drug addiction. Like Holmes, Mr.Downey, 43, has a mind so active it seems to run ahead of itself. He craves constant stimuli, partly for his own intellectual nourishment and partly, you suspect, to keep his demons at bay. “He’s the archetype of a tortured perfectionist,”Mr.Downey said of his character.


Susan Downey, a producer on the film and Mr.Downey’s wife, said Holmes is“a bit of a ladies’ man, a bit of a brawler,”adding: “He has a gambling problem. If you’re a Sherlock Holmes fan who is in love with the original stories, then you’ll appreciate him.”


Arthur Conan Doyle’s tales set the stage for the classic Holmes-Watson relationship,“the relish of language and the cerebral tennis matches that go on between them as they unravel this mystery,”as Mr. Law described it.


But Conan Doyle appears to have conceived his detectives as action characters, too, alluding to Watson’s military service, to boxing matches and gunfights, and to Holmes’s use of the martial art baritsu (he most likely meant bartitsu).


“So many of the ideas that Conan Doyle had took place offstage in his books,”Ms.Downey said.“We have the technology, the budget and the means to carry them out.”


Another question, since the movie is meant for a family audience: Drugs? No, Mr.Wigram said, speaking of Holmes.“He doesn’t do cocaine in our movie.”


By SARAH LYALL