‘Hancock': Stuporman, By Kurt Loder

Will Smith and Charlize Theron light up an almost-classic action fantasy.

John Hancock (Will Smith) is a new kind of superhero. He’s a mess. One night in Miami, after a mugging, he woke up in a hospital with no money, no ID and not a clue who he was. When a nurse asked for his John Hancock on a form, he gave it to her and then kept the name for his own. That was 80 years ago. Today, Hancock is an L.A. street drunk with a mean disposition and some offbeat abilities. He can fly, for one thing. And he can pick up a car with one hand and stop a speeding locomotive with his fist. Also, as he tells his new friend Ray Embrey (Jason Bateman), “I don’t age.”

“Hancock” works the slickest twist on the superhero movie since “Unbreakable.” In M. Night Shyamalan’s 2000 film, the nature of the narrative subterfuge evolved slowly, through an accretion of odd details and sudden iconic images. In “Hancock,” however, the plot twist is a delightful shock; it comes winging in from way out of left field and it transforms the picture. Unfortunately, it also forces the movie into an ending that makes not even a tiny bit of sense. But even a flawed classic is rare enough, and “Hancock” is a small classic of its kind.

Ray meets Hancock when the shabby superhero saves him from being flattened by a train. He already knows who Hancock is, of course; everybody does. When he’s not passed out in a nest of empty bourbon bottles, Hancock spends his time flying around town fighting crime and saving people’s lives. Everybody hates him, though, because with all his good deeds he does a lot of damage. Every time he comes soaring down out of the sky, he tears up 50 feet of neighborhood asphalt. When he tosses a beached whale back into the ocean — hurling it like a big blubbery discus — it naturally lands on a passing yacht. Lawsuits are piling up. TV host Nancy Grace is calling for his scalp. There’s a warrant out for Hancock’s arrest (as if any jail could hold him).

Ray, a PR guy who’s too goodhearted for his own good, knows exactly what Hancock needs: an image makeover. He takes him home for dinner, where Ray’s young son (Jae Head) is thrilled, but his wife (Charlize Theron) is appalled by Hancock’s surly lack of social skills, and maybe something else. Ray advises his new client to turn himself in to the police and voluntarily do some jail time. Hancock reluctantly agrees. With the sourpuss superhero behind bars, the L.A. crime rate shoots up 30 percent, and soon, at the sheriff’s request, Hancock is back on the crime-fighting beat, now togged out in a neat black-leather superhero costume (Ray’s idea) and doing his best to be polite to people (it’s hard).

The first half of the movie is very funny, as we watch Hancock grumping at the citizenry (to a staring old lady: “I’ll break my foot off in your ass, woman”) and butting ahead of some cute kids lined up at an ice-cream truck. (He’s just extinguished a burning building. He needs to cool down. Why can’t anybody understand?) The big plot turnaround — which comes about halfway through the picture, and which you have to experience for yourself — is pretty hilarious too (it also involves a rousing, sky-high battle-chase that trashes property values all over town). From this point on, though, the movie’s tone shifts radically. It grows darker and more earthbound, and at the end it stretches toward tragedy. This almost works, except that the plot point on which it depends — let’s say it’s the crucial importance of nearness and distance — is glaringly self-contradictory, and leaves us feeling let down and a little grumpy ourselves.

But “Hancock” is still a lot of fun. Will Smith remains one of the most likable of movie stars, and he’s a virtuoso of underplayed sarcasm. (He also gets props for risking his box-office rep on such wild material.) Jason Bateman is used mainly for his unassuming sweetness, and his character begins to fade in the second half of the picture. But Charlize Theron, radiant as always , expands her already remarkable range with a display of sharp comedy skills.

Despite its heavy complement of expensive digital effects, the movie doesn’t really feel like a holiday blockbuster (it’s only about 90 minutes long). It looks raw and grainy (it might have benefited from a little more visual stylization), and director Peter Berg is way too fond of 360-degree camera-twirling. But the story is unusually inventive and the script is filled with crisp, snappy dialogue, for which writers Vy Vincent Ngo and Vince Gilligan deserve a fee-boost for their next feature. They also need a good talking-to about that ending, though.

Check out everything we’ve got on “Hancock.”

For breaking news, celebrity columns, humor and more — updated around the clock — visit MTVMoviesBlog.com.