Guy Ritchie's Sherlock Holmes films are big and loud and noisy--probably a bit more than they need to be--but he's keenly attuned to what it takes to keep a modern audience's attention: move fast, talk faster, lots of fistfights, blow some stuff up. It was a formula that worked for his original 2009 Sherlock Holmes, and he doesn't go mucking with it in the new sequel, Sherlock Holmes: A Game of Shadows; he's found a style that works, and he indulges it. The results are occasionally uninspired, but good-natured fun all the same.

That inaugural outing ended with the introduction of the famed detective's nemesis, the notorious Professor Moriarty. He's played here by the great Jared Harris (best known, on these shores at least, for his work on Mad Men), and his presence is the primary new attraction; Harris plays the arch-villain with ice in his veins, and knows that there's nothing creepier than a brilliant madman with a thing for opera. The screenplay by Michele and Kieran Mulroney concerns the evil professor's attempts to use an anarchist bombing campaign to set off World War I, from which he'll profit handsomely.

There's also some business with a mysterious gypsy woman (Noomi Rapace, the Lisbeth of the original Dragon Tattoo films) searching for her missing brother, but all of that is just plot; what the movie is about, as with the first go-round, is the relationship between Holmes (Robert Downey Jr.) and Watson (Jude Law), which begins with the latter's stag party and wedding, though his honeymoon is quickly derailed by Holmes's latest case (and Moriarty's attempt on the lives of Watson and his bride). The real masterstroke of the first film, beyond its action beats and bare-knuckle brawling, was the notion of Holmes and Watson as the original buddy team; thankfully, that Butch & Sundance on Baker Street vibe remains intact, their best dialogue scenes a series of one-word exchanges, volleyed to and fro with brisk, impeccable timing. As before, Downey is an ideal mixture of brains, wit, and strength, while the underappreciated Law is a sturdy and capable sidekick.

Ritchie trots out some of the same flourishes this time around, and maybe that "see the fight before we see the fight" thing will get old eventually, but it hasn't yet. (It also helps offset the director's continuing tendency to shoot his action scenes too close and too fast). But the clockwork precision of his big set pieces is impressive--the train sequence, in which Holmes craftily thwarts Watson's attempted murder, is executed masterfully, those little burps in time well employed.

The picture is not without its stumbles. A close-up on a key prop early on badly contrives the long run-up to its reveal towards the end; how little attention do they think we're paying? Stephen Fry, as Holmes's brother Mycroft, is a welcome addition to the series, but his unfortunate nude scene is a cheap and rather nonsensical laugh (particularly since Ritchie's sense of visual comedy is, otherwise, spot on). And the gunplay of climax gets old pretty fast, though the filmmaker does his best to put a stylish spin on it. Yes, it's cool--it just belongs in a different movie.

Ultimately, Sherlock Holmes: A Game of Shadows lacks the jolt of freshness found in the reinventions of its predecessor. That, alas, is the curse of sequels forevermore. But it's a spirited good time, executed with wit and revelry, and that ending is a real humdinger.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.