People often ask me how many times I see a movie before reviewing it, and with rare exceptions the answer is "Just once." But a week and a half after I saw Sherlock Holmes, I found that the film had all but disappeared from my mind, and so I went back to see it a second time. I don't think it was just the usual clutter of holiday releases that caused the memory of this one to vanish like a mirage. Directed by the compulsively in-your-face Guy Ritchie (RocknRolla), Sherlock Holmes is an odd amalgam, a top-heavy light entertainment that keeps throwing things at you and doesn't seem too concerned with whether they stick.
Sherlock (Robert Downey Jr.), the venerable sleuth of 1880s London, is still a master of deduction, sniffing out clues that are invisible to everyone else. But he is now, in addition, a crowd-pleasing man of action who leaps out of buildings, dodges explosions, and engages in the occasional ultraviolent bare-knuckle brawl. He and his comrade, the genial Dr. Watson (Jude Law), are still partners in crime-fighting, but they're also whimsical, nattering fops who carry on like old college roommates sharing private jokes for which you really had to be there.

The film brims with "colorful" London-cobblestone backlot atmosphere — which sounds like a good thing, except that Sherlock Holmes is often as busy and crowded as a musical, so that the background frequently threatens to engulf the foreground.

Oh yes, I forgot: There is also…a detective plot. It rests on some shady business about a slime named Lord Blackwood (Mark Strong), who is tried and hanged for murder — Dr. Watson is on hand to ensure that he's dead — but who then mysteriously rises from the grave so that he can launch a plan for world domination. If that sounds like an extravagant ambition for a Sherlock Holmes villain, the whole movie, in its popcorn way, is bumptiously extravagant; it's like a 19th-century National Treasure sequel crossed with an episode of the old Batman TV series. All of which would be fine if it added up to a crackerjack entertainment, but Sherlock Holmes, while a diverting enough night out, is both fun and numb, enjoyable and exhausting. It's a case of more adding up to less.

The best thing in the movie is Downey. As Holmes, he's rumpled and amusingly jittery, an investigator who lives on his own plane of perception and can scarcely be bothered with anyone else's. There's an authentic Sherlockian intensity about him. Early on, the film shows us that Holmes is a creature of deduction even in the middle of a fistfight: In the space of a few super-slo-mo seconds, he literally thinks out the half-dozen punches he's about to throw. Downey, analyzing each blow (and the damage it will cause) with his puckish British inflections, transfixes us with his casual command. Each time that Holmes actually has to figure something out, Downey widens those dark saucer eyes, which are shot so they're pools of black; he's hypnotic. The movie, unfortunately, isn't really built around Holmes' deductions. They're more like brainy little hermetic games sprinkled along the way. Even his ability to deconstruct a fight is introduced only to be forgotten.

Since Sherlock Holmes is the kickoff to a franchise, it might for once have been terrific if the movie had been an origin story, with Holmes discovering his lightning powers of intuition. But Sherlock Holmes, with its jaded hero, jumbly overkill, and skittery mystery plot, is more like a part-five sequel made by people who were forced to put on a big show of conviction. The whole movie is a put-on — it's a smoke-and-mirrors blockbuster. Mark Strong, as the villain, looks like Andy Garcia as a hulking Dracula, but apart from that there's not much to him, and Rachel McAdams, as a former lover of Holmes', now with murkier loyalties, is enticing in such a sweet Victorian way that it seems perverse for the movie to muffle the romantic spark between her and our hero. The real "love story," of course, is the jokey, stiff-upper-lip, entirely fraternal bromance between Holmes and Watson. Their muttery ironic joshing has a certain out-of-time talk-show cleverness, but like the movie itself it holds your attention even though there's never really anything at stake.