There's a scene in Iron Man 2 when James "Rhodey" Rhodes puts on a prototype suit to stop a drunken Tony Stark from endangering guests at a party. This leads to a pointless fight between them, with a great deal of collateral damage to their surroundings, that puts those guests in more danger than they were in before.

It's that kind of sloppy logic that makes Iron Man 2 less impressive than Iron Man.

Iron Man and Iron Man 2 are, in case you've been living under a rock, among the latest and most spectacular comic-to-movie adaptations to hit the big screen. Based on the hit series from Marvel Comics, they are part of an ongoing saga leading up to an Avengers ensemble film in 2012.

There are a lot of elements at play in this installment, most of which revolve around several key points:

• The U.S. government wants Iron Man technology for the military.
• Other world governments are trying to develop similar tech, but are failing -- although a brilliant but unwashed Russian physicist, building upon schematics more than 30 years out of date, is able to recreate and even improve upon Stark's cutting-edge design. He's not working for fame, profit or patriotism, however; his sole motive is his hatred for the Stark family name.
• A competing U.S. defense contractor isn't as smart or successful as Stark, but he's willing to consort with criminals to achieve his aims.
• S.H.I.E.L.D., a peacekeeping agency operating outside normal government channels, wants Iron Man on its side -- but isn't sure Tony Stark is a necessary part of the package.
• Stark is dying, poisoned by his own technology.

That's a lot of balls to juggle. And IM2, directed by Jon Favreau, manages to keep some of them in the air.

But this sequel, operating (as the climactic scene will attest) on the theory that more is always better, never finds its stride. The result is a bit of a mess, including some niggling details that don't sit well. Here are a few examples -- these are minor spoilers at best, but if you want to avoid them, just skip down past the italics.

• The government wants the Iron Man suit. Stark refuses to share it. So best friend Rhodey, peeved that Stark got drunk and partied down in the armor, simply steals it.
• The Iron Man suit is irrevocably tied to the one-of-a-kind power generator imbedded in Stark's chest, yet Rhodey operates the spare suit just fine without one. Rhodey also manages to fight and hold his own against Stark without any training or experience in the suit's use.
• The element powering the suit is slowly killing Stark by increasing toxicity levels in his blood. The special batteries Stark uses to fuel the reactor keep burning out. These two very different problems have a single solution that involves creating an entirely new element, which Stark accomplishes in a matter of days. His solution involves a formula discovered by his father more than three decades previously -- even though his father had no way of anticipating the need -- and hidden in a coded map that can only be broken using 3-D technology that didn't exist back then.
• Oh, that scene in Monaco? You'll know the one I mean. How did the bad guy know in advance Stark would be driving that car?

For all its weaknesses, Iron Man 2 has many strengths, too. The special effects in particular are beyond reproach. And, while IM2 lags a bit in the middle, it certainly packs a lot of energetic comic-book mayhem into two hours' of film.

As Stark, Robert Downey Jr. is, of course, completely wonderful in this film. He personifies Stark well, tapping handily into Stark's narcissism, his ego, his undeniable brilliance, his bedrock conscience and unshakable sense of responsibility, his childlike desire for immediate gratification, his fear of death, even his embarrassing alcoholism.

We have, not one, but two lead actresses, both of whom are excellent in their roles -- and, unfortunately, completely wasted. Pepper Potts (Gwyneth Paltrow), indispensable in Iron Man, spends most of this film on the sidelines, angry and irrelevant. Meanwhile, superspy Natasha "Black Widow" Romanoff (Scarlett Johansson) makes a dynamic entrance into the film but, as nice as she is to look at, doesn't have much purpose until the end, when she finally gets to kick ass in a skintight suit. Neither character is necessary to the plot.

Don Cheadle makes a good effort to replace Terrence Howard as Rhodey, but he comes across as stiff and uninteresting.

On the side of the devils, we have Ivan Vanko (Mickey Rourke), who slaves away in a dingy Russian lab to best Stark at his own game without ever taking a bath. Obsequious defense contractor Justin Hammer (Sam Rockwell) tries to play at Stark's level, with comedic results. You just know these two guys are going to get together.

Bottom line, Iron Man 2 is a flashy, fun-filled movie that continues the excellence set by Iron Man without achieving the same level of success. Superhero fans will love it, endlessly debating its worth when compared to the original, as well as recent Spider-Man movies and, of course, the most recent Batman experience. Ultimately, the plot holes won't matter so long as people eat up the action and special effects.

I just hope the next one does a better job tying it all together.