Slingin' it.

HOW do you kill off Spider-Man? I've puzzled over that question through all three installments of Sam Raimi's Spider-Man saga, and the answer still eludes me. The spider-bite that transformed Peter Parker, uber-nerd, into a wall-crawling, webslinging superfreak obviously augmented his strength to near-Superman proportions, enabling him to lift buildings off his lady love and yank speeding trains to a screeching halt. But more impressive than his strength is his physical resilience: He survives plunges from heights that would kill a lesser superhero, gets sideswiped by speeding trains without skipping a beat, and lasts a lot longer than you or I would while getting smashed, repeatedly, by the fist of a seven-story-tall sand monster.

This last sequence takes place near the end of Spider-Man 3, and it isn't a good sign for the franchise that I was more invested in figuring out what it takes to kill off Spidey--four punches from the Sandman's elephant-sized fists? five? six?--than in anything else that had happened on screen in the previous two hours. There are rumors that this was the most expensive movie ever made, eclipsing even the inflation-adjusted price of the Taylor-Burton Cleopatra, and the money wasn't exactly spent in vain: Spider-Man 3 is stuffed like a Thanksgiving turkey, with more villains, more love interests, more special effects, and (alas) more dance numbers than the previous two movies put together. Indeed, given the price tag, I suppose it's almost understandable that a Sony Pictures accountant looked hard at the balance sheet and decided that if they were going to finance all that CGI, they couldn't afford to shell out for a screenplay too.

Or maybe they splurged on four screenplays and then hired a team of baboons to run them all together. That's a more likely explanation for why Tobey Maguire's Peter Parker ends up battling not only Thomas Haden Church's Sandman, a convict-turned-shape-shifter, but Venom (Topher Grace) and the New Goblin (James Franco, donning Willem Dafoe's Goblin gear from the first movie) as well, while contending with a collapsing romance and a black-goo symbiote from outer space that "amplifies characteristics of its host"--which in Peter's case, to judge from the bangs-over-the-eyes haircut he sports after bonding with the goo, means getting in touch with his inner indie rocker.

That this transformation is supposed to be sinister rather than hilarious is just one of the many problems with Spider-Man 3. Or at least sometimes it's supposed to be sinister, injecting a note of Batman-style inner turmoil into Spidey's candy-colored world; the next moment, though, Raimi is playing the symbiote-infected Peter for laughs, sending him swaggering down the street in a Eurotrash suit, practicing his dance moves and winking at horrified women. I laughed, all right, but then again I also laughed at the Sturm und Drang that followed, with Tobey Maguire bare-chested in a church belfry, tearing the symbiote off himself and howling, to a swelling score, with all the pathos of a bad King Lear impression.

Worse than the tonal problems, though, are the endless ex machina moments, where the movie seems to be deliberately insulting the audience's intelligence. Every comic-book film climbs Mount Improbable, and no summer-movie aficionado would bat an eye at the possibility of a black goo from outer space, or a particle-physics experiment that turns a mournful escaped convict into a shifting, eddying sand creature, or a supersoldier serum and a flying skateboard that enable a tycoon's son to match Spider-Man blow for blow. But when the meteor carrying the black goo happens to land ten feet from the web where Peter and Kirsten Dunst's Mary Jane are making out, with no explanation save coincidence, the audience grows restless; when the Sandman happens to be the real killer of Peter's uncle, thus undercutting a major plot point from the first movie and suggesting a certain stakes-raising desperation in the filmmakers, the grumbling grows louder; and when the tycoon's son turns out to have a butler, heretofore unglimpsed, who happens to offer a crucial revelation at a crucial moment without explaining why he never mentioned it before, the only appropriate response is heckling, or maybe giggles.

There are bright spots: Haden Church's metamorphosis into the Sandman is a small masterpiece of digital effects, and a tear-drenched movie's only moving moment; Franco, who moped his way through the previous film, gets to have a little fun with his part this time around; and the early scenes where Peter basks in Spider-Man's city-wide celebrity have a little of the infectious "What if you were a superhero?" charm of the first two movies. But for the most part, Raimi wastes his resources: Haden Church gets half the screen time he deserves and Grace has about a quarter; a radiant Bryce Dallas Howard, as Mary Jane's rival Gwen Stacy, is hustled into the storyline and just as quickly hustled out; and fine character actors like James Cromwell and Theresa Russell are squandered in blink-and-you-miss-them cameos. Meanwhile, the holdovers from the earlier films aren't aging well: Peter's Aunt May (Rosemary Harris) bustles around, preachy as ever and increasingly unbearable, and Dunst herself, wan and haggard-looking, seems to have lost interest in these films, or maybe life itself.

The only good news for moviegoers is that Spider-Man 3's longueurs and laziness suggest that its director may finally be tiring of the project. For Raimi, the superhero movie has been a kind of cinematic symbiote, amplifying his moneymaking but sapping his artistic promise. Before taking up with Spidey, he made the modest, harrowing Great Plains noir A Simple Plan, which didn't earn the bazillion dollars that Spider-Man 3 will doubtless gross, but did hint at grown-up talents that have since lain fallow. I like to think that Raimi was watching that movie in his trailer while this one spiraled into folly, and that the inevitable Spider-Man 4 will have someone else's name on it, while he moves on to smaller, better things.