Avengers: Age of Ultron
★★★★
Opening Friday

Part of the fun of following movies—especially science-fiction movies—is seeing how they reflect our current cultural anxieties. Stories about artificial intelligence go way back, through Blade Runner and 2001: A Space Odyssey all the way to Metropolis. Recent entries such as Ex Machina and Her have updated the genre with queasy psycho-sexual elements. The idea of artificial intelligence clearly freaks us out, as a people.

With Avengers: Age of Ultron, director Joss Whedon’s superior popcorn movie, the A.I. story gets plugged into a comic-book template. It’s a perfect fit. The A.I. threat is more fiction than science—at this point, anyway—so we might as well have some fun with it.

The set-up is based on a 2013 comic-book storyline. A rogue A.I. by the name of Ultron, voiced with delicious oiliness by James Spader, is out to destroy the Avengers, all of whom return from Whedon’s summer 2012 hit of the same name. Earth’s Mightiest Heroes, in order of movie-star wattage, are Iron Man (Robert Downey Jr.), Black Widow (Scarlett Johansson), Captain America (Chris Evans), Thor (Chris Hemsworth), Hulk (Mark Ruffalo) and poor old Hawkeye (Jeremy Renner).

Whedon’s script—a marvel of blockbuster efficiency—makes time to dig into each character’s comic-book psychology, including needling Hawkeye about his second-banana skill set. “We’re fighting an army of robots and I have a bow and arrow,” Renner laments. “None of this makes sense.” The movie never takes itself too seriously, and Whedon amplifies the jokey tone of its predecessor with funny dialogue and running gags. “Pretending we need this guy really helps bring the team together,” says one of Hawkeye’s colleagues. Ya burnt!

Of course, superhero movies need epic heroics as well, and the goods are delivered in stunning CGI showcases and inventive action sequences. Dozens of visual-effects studios are listed in the credits, and thousands of technicians worked on this thing. Much of the fighting involves the Avengers swatting away Ultron’s army of robot goons in spectacular fashion. One-on-one boss fights get their own kinetic set pieces, including an epic showdown between Iron Man and a rampaging Hulk.

CGI-heavy battle sequences like these can easily spin off into visual incoherence, but Whedon and his team assemble each scene with an eye to proper structure and pacing. It’s so hard to get this stuff right, and it’s so miserable when it’s done wrong. There’s even an A.I. versus A.I battle that takes place entirely in some notional digital realm, and the filmmakers find a way to make that work, too.

The sequel introduces some new characters and brings back some Marvel movie vets. Elizabeth Olsen is the most interesting new addition as the Scarlet Witch, a troubled hero with semi-mystical psychic powers. Aaron Taylor-Johnson plays her twin brother, Quicksilver, whose super-speed abilities trigger some wild FX sequences. Paul Bettany, the voice of Iron’s Man’s computer sidekick J.A.R.V.I.S., reprises that role, but, in a cool twist, now in an android body as The Vision.

Familiar characters include War Machine (Don Cheadle), The Falcon (Anthony Mackie) and ex-government operative Maria Hill (Cobie Smulders). Samuel L. Jackson returns for a couple of scenes as Nick Fury. The storyline aims for continuity with previous films in the Marvel Universe, as well as the TV shows Agents of S.H.I.E.L.D. and Agent Carter. Hardcore fans will be pleased to see tightly scripted additions to the overarching Infinity Gems storyline.

As a movie-going proposition, Avengers: Age of Ultron is a square deal. Whedon delivers style and spectacle, and I’d recommend seeing the movie in IMAX 3D if you can. In for a dime, in for 15 dollars, I always say. Fans of thinkier science fiction won’t find a lot to hold on to, but beneath all the bombast, Whedon’s script turns on some interesting ideas about A.I.

After you see the movie, consider how and why Ultron gets loose, and note his recurring catchphrase. As a storyteller, Whedon has always been mischievous with his pop culture creations—Buffy the Vampire Slayer, Firefly, Dollhouse. He likes to bury quiet twists and subversions in his genre exercises, and his villain here isn’t some space alien or Asgardian deity. He’s a machine of our own making, with personal and political agendas—human fallibility deep in his digital DNA.