Sherlock Holmes: A Game of Shadows, the bigger, louder sequel to Guy Ritchie's slambang reinvention of Sir Arthur Conan Doyle's much-revered detective series, could have been called The Case of the Runaway Red Herrings. Virtually every set-up and set-piece in this extravagantly tedious adventure is misleading, or worse, irrelevant.

As Holmes (an eye-popping, eyebrow-tweeting Robert Downey Jr.) and Watson (a spry Jude Law) dash around 1891 Europe on the trail of the criminal mastermind Moriarty (Jared Harris), they encounter Gypsies and Cossacks, they climb aboard ships and trains, they drive a horseless carriage and, comically, Holmes commandeers a wee pony. They even cop a scene from Pulp Fiction.

And every occasion offers Holmes the chance to bare his knuckles and engage in dizzying mixed martial arts business. The press notes for Game of Shadows dub Ritchie's trademark slo-mo/sped-up action sequences, and his hero's ability to visualize the moves of his opponents before they make them, "Holmes-O-Vision." There's so much Holmes-O-Vision going on here, the producers could spin it off into a whole other feature.

There's nothing wrong with making the ratiocinating resident of 221B Baker St. a brawling badass, if the filmmakers had also honored Holmes' uncanny talents for deductive reasoning, his powers of observation and forethought. But the intellectual side of Downey's Holmes is represented by not much more than show-off blather and far-fetched "reasoning." Not a keen mind so much as a careening script.

Game of Shadows is a buddy movie, too, in which the women are pushed to one side (or literally pushed from a train) so Holmes and Watson, casting admiring gazes at one another, can trade badinage and banter. The fact that Downey's Holmes finds an excuse to doll up in a woman's frock, curls and rouge only adds to the, um, buddyness of the proceedings. (Not that there's anything wrong with that, as they used to say on Seinfeld.) And so there's no place for the just-betrothed Mary Watson (Kelly Reilly), nor for the first movie's femme fatale Irene Adler (the impossibly un-fatale Rachel McAdams), who makes an early exit here. Noomi Rapace, the original Lisbeth Salander in the Swedish adaptations of Stieg Larsson's Millennium Trilogy, has some serious action cred of her own, though, so she's allowed to tag along with the boys. She's Madam Simza, a soothsaying Gypsy whose brother is somehow involved with Moriarty.

As for the Professor, he is touted as "the Napoleon of crime," and toward the end of Game of Shadows - after the cannon fire, the exploding munitions factory and the lethal business at the Paris Opera - Holmes and Moriarty meet. And play chess, of course.

The two antagonists are so brilliant that the board becomes redundant - they stand facing each other, one bent on good, the other evil, and call out their respective moves, visualizing the match in their heads.

And then it's off to Reichenbach Falls in the Swiss Alps, which, as even the most irregular of Baker Street Irregulars already knows, is a fateful place. No spoilers here, but suffice to say that when Dr. Watson types "The End" on his account of Holmes' latest adventure, the finality of such words should not be taken seriously.