1. Other than that terrible Todd Phillips-Zach Galifianakis comedy Due Date, Robert Downey Jr. hasn't played a character other than Tony Stark or Sherlock Holmes in four years. Of all the actors who could have ended up settling into tentpole action star roles? Downey? I caught Robert Altman's Short Cuts again recently, and while Downey has a small, minor role, I was taken aback by how compelling and terrifying he was, just on sight. He was just as shiftily charming then, but in that sort of mad, apocalyptic, drug-addled '90s way. He seemed headed for a career of playing doomed, insane poets for a few years until someone found him in a hotel somewhere. He was going that way, too—remember all his arrests, the Ally McBeal recovery period, and the time he lost his part in Woody Allen's Melinda and Melinda (and was replaced by Will Ferrell) because he couldn't get insured—until he turned around. And, amazingly, he turned into this.

2. You can make a pretty strong argument that the Marvel movie universe, and its billions in profits, exists because of Downey. Iron Man was the first wholly Marvel-made movie—the X-Men and Spider-Man franchises, among others, had been licensed out to other studios—and it was a massive hit. That was due entirely to the combination of Downey and director Jon Favreau, who understood that they needed to bring an entirely different sensibility to the superhero movie, less hero worship and more postmodern, semi-cynical entertainment. That sensibility infused some energy into some pretty square superheroes—I mean, even the movie about freaking Thor was kinda fun—and led to the brilliant, ridiculously profitable decision to put Joss Whedon in charge of The Avengers. The whole thing was born from Downey finding the perfect role, and knocking it out of the park.

3. Iron Man 3 doesn't have that anarchist, game-for-anything feel of the first film, but it's tons more fun than the dreadful second one. (I'm pretty sure Mickey Rourke was asleep for half that movie.) Its premise is your basic hero-falls-from-grace-and-must-be-reborn arc, the one Christopher Nolan has mastered. An evil terrorist supervillain called The Mandarin (played by Ben Kingsley) has some sort of new bomb that leaves no trace, and he wants to destroy the United States and the President, specifically. When Stark butts his nose in, the Mandarin, along with some shady helpers from some technology corporation (led by a sneering, enjoyable Guy Pearce), basically destroys his life, kidnaps Pepper Potts, and forces Stark to start over completely, figuring out who, exactly, that man underneath the suit really is.

4. The movie is directed by screenwriter Shane Black, and it moves along nicely, even if there are a ton of story holes that aren't worth worrying too much about. (There are several scenes where characters just show up where the story needs them to be at that exact moment, without explanation.) The villains, always key in a superhero movie, are perfectly adequate, and while the movie gets bogged down with a dull, cloying subplot with a Helpful Adorable Child Who Assists Our Hero In His Darkest Hour, it more than makes up for it with some ripping action set-pieces. The movie certainly hits its obligatory summer-movie marks, from a wild escape from a crashing plane to the ohhh shit moment when Stark summons dozens of identical Iron Men. It doesn't skimp on the big stuff.

5. But the movie mostly cooks because of Downey, who, as always, keeps up a funny, rollicking meta-commentary on the action while engaging right in the middle of it. There's a side story about Stark suffering post-traumatic stress after the incident at the end of The Avengers that doesn't quite work—no one wants to see a self-doubting Tony Stark—and seems included just to remind you that Tony Stark was in that movie. (And to keep the franchises tied together, of course.) But everything else, from the large-scale explosions to the little moments with a never-more-charming-than-in-these-movies Gwyneth Paltrow, Downey nails. I don't know if they're going to make an Iron Man 4, but the way it's looking, Downey's gonna be around to play this character, in various movies, as long as they keep making money. I'm all right with that. Maybe Downey didn't end up being the crazed poet who changed the world, but the way he turned out is just fine.

Grade: B.