The “Iron Man” movies have become the thinking person’s superhero franchise if for no other reason than that they feature the thinking person’s movie star. Alone among his be-muscled and be-spandexed brethren, Robert Downey Jr. clearly considers the whole enterprise vaguely ridiculous.
Still, he risks being trapped in that can. “Iron Man 3” is the weakest in the series, and it suffers from confused plotting, flat-footed exposition, and more pure, noisy nonsense than even a comic-book movie should have to put up with. Yet whenever Downey is being Downey, it’s still the most subversive Marvel franchise around. There are bad guys who glow like nuclear briquettes, fireballs and detonations, collapsing mansions, crashing airplanes — and the best scenes are when the star just cuts impatiently through the claptrap. Full story for BostonGlobe.com subscribers.