Sneaky superhero movie! Another caped-crusader tradition gave us the idea that heroes who don't die in the line of duty live to become villains, but The Avengers lets it play out onscreen. The bad guys in Age of Ultron? Tony Stark and Bruce Banner. For real.
Tony's villainy is externalized in Ultron, an AI creation that he has been working on for years and can finally bring to fruition now that the Avengers have reacquired Loki's wondrous scepter from what's left of Hydra (this is the opening sequence of the film). Ultron (the voice of James Spader) has some of Tony's (Robert Downey Jr.'s) attitudes, but a glitch in its "birth" makes it go a bit cyber-insane, and it interprets Tony's notion of world peace to mean "a planet without humans." Now it's gotten loose and must be stopped.
It's not so much the twisting of Tony's attitude that's the villainy here, but that Tony was keeping yet more secrets – and Ultron is a huge one – from the people who are supposed to be his partners in saving the planet. The rest of the Avengers learn about this new danger after it has tried to kill them all. This literally ruins the Avengers' party.
In poor Bruce Banner's case, though, it really is he who has become a menace. Well, the Hulk has, anyway. In the middle of a battle rage that gets even more out-of-control than usual, he goes on a rampage that causes massive destruction in downtown Johannesburg. He is stopped only when Iron Man – in Hulk-scaled power armor – steps in, and it's not an easy thing. It's a fairly horrifying sequence, watching friend forced to battle friend and knowing that Bruce doesn't want to be doing this (never mind what the innocent injured people of Jo'burg must be feeling). His horror once he has transformed back into his human self continues through the rest of the film – Mark Ruffalo is fantastic – and is tough for us not to share in. The Hulk is dangerous to everyone, not just bad guys.
Tony and Bruce have finally gone full mad-scientist. It's a fascinating upending of genre tradition that might make this flick work for nonfans, even though it assumes a lot of familiarity with what's come before in the series – such as that you'll know what Loki's scepter and Hydra are about without having to be told.
It's not all gloom, though. Director Joss Whedon ensures that Ultron continues the Avengers tradition of big, bold action blockbusters that don't need to toss away thoughtfulness to remain pure popcorn fun. Tony and Bruce's second-guessing of their work is more comic-book soap opera than serious drama, as are some of the other things we learn about the personal lives of the Avengers here: Romance is budding between Natasha (Scarlett Johansson) and Bruce, though she has to push it a bit; and Clint, aka Hawkeye (Jeremy Renner), turns out to have a surprising secret. The finale is truly sci-fi superhero action movie whackadoodle, taking urban destruction to a new (antigravity-assisted) level.
The film isn't without problems. Urban destruction – Seoul also takes a beating here – is getting old. The effects in the opening attack-on-Hydra sequence are surprisingly cartoonish. And 45-minute battle finales have to go: It's overkill, and we've had enough. Can we find something new for these movies to do?
The cool thing is, Age of Ultron ends by suggesting that yes, maybe we can. Big changes are initiated here that indicate that the team, at least, is going to be very different next time out. This franchise isn't afraid to move on from aspects that aren't working anymore, and here any tiredness in the characters is confronted directly and dealt with. When I say that this is the weakest of the Avengers movies so far, I don't mean that it isn't still hugely enjoyable. And any complaints are mollified by the hint that this huge ongoing story won't be refreshed as needed.