Why are Peter Parker and Spider-Man never in the same place together? Hmmmm... Spider-Man Starring Tobey Maguire, Kirsten Dunst, and Willem Dafoe. Directed by Sam Raimi. Written by David Koepp, based on Stan Lee and Steve Ditko's comic book. Rated PG-13.

The first blockbuster of Hollywood's summer season, Spider-Man, isn't all bad. It's worse than that. Why? Because while a lot of it's bad, some of it is good enough to give you a glimpse of what this comic book adaptation could have been. And that's frustrating enough to make you crawl up a few walls.

The movie rings a few changes on the familiar story created by Stan Lee and Steve Ditko. Nerdy photographer Peter Parker (Tobey Maguire) and the girl he's sweet on, Mary Jane "MJ" Watson (Kirsten Dunst), are high school seniors when things start to change. While touring a bioengineering lab, Peter is bitten by a genetically souped-up spider -- not a radioactive one, as the original has it -- and he suddenly acquires the spider's powers. At first, he revels in his improved strength and reflexes, his ability to cling to walls and ceilings, and his ability to shoot spiderwebs from his wrists. One day, however, he refuses to stop an armed robber, and the man later ends up killing Peter's beloved Uncle Ben (Cliff Robertson). As a result, Peter devotes his powers to fighting crime.

It starts off well enough. The comic-book Peter Parker is too bland, so Maguire is a sterling choice to make him interestingly weird. When his Aunt May (Rosemary Harris) says, "You've been acting strange lately," he responds, "Thanks." Director Sam Raimi puts his flair for outré visuals to good use -- when Peter's body starts to change, we get a picture of tiny spiders crawling around on his, well, what are those, blood vessels or DNA strands? The humorous touches work well, and the first Spider-Man costume is a hilarious gag. The movie's high point comes when Spider-Man first uses his webs to swing through the air among the skyscrapers -- the camerawork and Maguire's ecstatic shouts of "Wooo!" make it a delirious kinetic thrill.

It all soon comes apart. The bad guy in this piece is the Green Goblin (Willem Dafoe), a.k.a. Norman Osborn, a wealthy defense contractor who goes insane and turns to crime after testing an experimental strength booster on himself. He also happens to be the father of Peter's best friend and rival for MJ's love, Harry Osborn (James Franco, who succeeds a bit too well at playing a weak character -- he seems ready to burst into tears in every scene.) As the bad guy, Dafoe overacts oppressively. Stylized performances come with the territory for actors playing comic-book villains, but whether he's playing the demoniac Goblin or the conscience-stricken Osborn, he constantly strikes the same notes. He never gives the sense that the two personas are opposite sides of one coin. J.K. Simmons demonstrates much better command of the required style in his performance as anti-Spider-Man newspaper editor Jonah Jameson.

The script is by David Koepp, who penned the first two Jurassic Park movies and, most recently, Panic Room. He has always been a hack, but here he sinks to depths that none of his previous work even hinted at. His weakness with female characters rears its head: MJ has nothing to do in the action sequences except scream for help. Kirsten Dunst deserves better than that. His atrocious dialogue reminds you of James Cameron or George Lucas on their worst days. ("Forty thousand years and we've barely even tapped the vastness of human potential!")

There's a lot of it, too -- Raimi lets long stretches of it interrupt the fight scenes, which are disturbingly amateurish. His films have always been up-front about the unreality of their special effects, so it could be just part of his style, but there's no dramatic buildup to Green Goblin's attacks. Between the dialogue and the unconvincing shots of combatants being punched through walls, the confrontations between Spider-Man and Green Goblin carry no dramatic weight. The whole plotline involving the Goblin is just radically misconceived, and the humorous and romantic interludes come off as inappropriate.

It's surprising that Raimi lets things deteriorate to this state, but maybe it shouldn't be. His filmmaking talents have always been unstable at room temperature. He can be powerfully tragic in one movie (A Simple Plan) and completely banal in the next (For Love of the Game). Raimi brings some good ideas to this film, but he doesn't have an overarching vision of what the whole Spider-Man story is about. Bryan Singer keyed X-Men to the theme of prejudice, and wound up with a comic book adaptation that didn't appeal to everyone but was much more consistent in tone.

Ironically, the theme he should have picked up is right there in that badly written script. The romance between Peter and MJ should have carried the film, especially since Maguire and Dunst have a fragile, touching chemistry. The film ends on a note of alienation and disappointment for the two characters, and the last scene is played as the finale of a romantic tragedy about a geeky kid who makes himself over into a successful man but loses his ability to trust and love others in the process. If the rest of Spider-Man had been that film, it might have been something. Unfortunately, too much other stuff got caught in the web.

You can reach Kristian Lin at kristian.lin@fwweekly.com.