Summer Finn, (Zooey Deschanel,) a twenty something office worker from a small town, almost accidentally becomes the dream girl of Tom Hammond, (Joseph Gordon-Levitt,) a would be architect marking time writing greeting cards. But while Tom seeks some kind of commitment, Summer stubbornly resists.

We know right from the start that this couple can’t last, but the comic tone tells us the movie will amuse us in spite of that. Director Mark Webb and co-writers Scott Neustadter and Michael Weber have chosen to concentrate on the small moments between the couples’ beginning and end, for the most part showing them with visual and spoken wit. They wisely set a level in the early part of the picture and remain true to it, so the content bears up to the weight of a fragmented, seemingly spontaneous structure. Turns out the structure is very well thought out.

The movie jumps around in time. Titles tell us the various days they spend together and apart, in no particular order. What we get are mostly anecdotes that recreate the feelings, mostly Tom’s, of what it was like to long for, briefly possess, and then to lose Summer. Along the way we spend a lot of time with Tom’s friends and his younger sister, all of whom seem to get what Tom doesn’t; that Summer will never really be his.

An omniscient narrator delivers a series of dry observations about the characters, for the most part unnecessary. The filmmakers, emulating Woody Allen here, seem a little too concerned with the details of Summer’s history. As it turns out their visual instincts and the assured eye of cinematographer Eric Steelberg tell us everything we need to know.

When it began I thought the story took place in Philadelphia or Chicago. The color palette was autumnal, the images softly urban. I was surprised when it was revealed to be down town LA, which has been selectively shot and edited to create a very different city than the one I know.

I believe what holds the movie together, and keeps it in your memory is its savvy view of who these people are. Introverted, introspective and articulate to a fault, Tom has a solid grip on the microcosm, but is clueless about larger emotional realities. Summer, on the other hand, appears to drift, but keenly senses what she feels. Gradually we see that her idiosyncrasies mask a better grounded interior.

The last few episodes elegantly summarize the problem and its resolution. But it isn’t a drag, it’s funny and sensible. Tom may be better educated than Summer. He may be smarter. But he can’t talk her out of her instincts. He simply does not have enough of what it takes for her to surrender to him, at least not at this point in his life. The filmmakers know this and express it with the minimum of sentimentality.

Is this the Annie Hall of its generation? Yes and no. It’s stylish and sharp like the Woody Allen, but narrower in focus. Allen always has one eye on the larger picture, of a possibly godless world and the consequences thereof. He’s always stopping to comment as he stares into what might be the abyss. His introverted attitude can make it feel like he’s the only one in the story who seems to realize the fragility of all human endeavor. “Summer’s” creators seem totally focused on the inner lives of their two leading characters. They don’t spend much time dwelling on the state of the world. The soundtrack, the supporting cast, even the settings, reinforce that point of view. Incidentally, a terrific songwriter/singer, Regina Spektor, contributes at least two great songs.

Tom’s work at the greeting card company is an easy set up for a host of pot shots at middle American values. Ok, we’ve all cringed at how easily our complex emotions are packaged and sold at three bucks a shot. But the environment plays well against the movie’s juxtaposition of its characters particular stage of life, even if the device is a little facile. After all, this is a comedy.

Joseph Gordon-Levitt is finally given the kind of role that shows him as the new age Dustin Hoffman. And Zoey Deschanel is a perfect foil for him. For the first time in a while she gets the space to delve into a character. She’s been good in other films, but her parts have been limited. This time it’s all about her. Instead of being used in a role she uses the role.

Like “Juno,” and “Little Miss Sunshine,” the distributor, Fox Searchlight has given “500 Days of Summer” the marketing push it needs to find a large audience hungry for relief from the bombast of the seasonal blockbusters. See it and enjoy.

Horror films can be as diverse as comedies, although lately most have followed the by now tired formula of popular “torture porns” like “Saw,” and “Hostel.” Worldwide, horror movies sprout like weeds, sometimes choking their better bred relations, like last year’s entry from Spain, “The Orphanage,” which made you uneasy without the need for an air sickness bag. (Look for the DVD)

Now comes M. Night Shyamalan, a superstar director, who takes the high road with a refined chiller that, like “Sixth Sense” and “Signs,” recalls other films at the same time it stakes territory of its own.

“The Happening” has its awkward moments, but it digs deep into your conscious and won’t let go. The story, about a virus that erodes and then mutates human will, effectively exploits our fears about suicide and isolation. It’s a thriller for those who have contemplated the potential effects of a neutron bomb, chemical warfare, or the breakdown of the global ecology. Cinematographer Tak Fujimoto renders the most pastoral settings with a taint of dread. Visual effects, used sparingly, subtly heighten reality, instead of trying to subvert it. Refreshingly, the most chilling moments occur in broad daylight. City streets and pristine forests suddenly turn imperceptibly lethal. Though you can’t see the menace you sense it lurking from the first shot.

“The Happening” is at its most disturbing when showing ordinary people in quiet free-fall; nervous survivors stuffing themselves at a diner, the entire crew of a commuter train gathered in a knot of confusion, a woman standing alone in her yard as a breeze blows through her hair.

Mark Wahlberg turns in a nuanced performance as an ordinary high school science teacher utterly incapable of coming to grips with disaster – like you and me. Zooey Deschanel, as his childlike wife, is less compelling in an underwritten part. But she’s physically right, and that helps. Shayamalan has been shrewd in the casting of many smaller parts.

There are false steps along the way. Some of the humor falls flat. The dialogue, at times purposely banal, comes close to alienating our affections for the characters. This is a function of the film’s larger ambition to focus on the ordinary, for which I can’t fault it. But as a writer Shayamalan has shown a firmer grasp of characters with broader pathologies, like the scared kid in “Sixth Sense,” or Mel Gibson’s lapsed preacher in “Signs.” Here, the bald messages his characters deliver are a bit artless.

For the most part critics have turned on this movie, but I think a lot of them so despise the writer/director’s well documented arrogance that they willfully slight his inspired filmmaking. This is ironic when just a month ago many of the same praised “The Strangers,” a stale and glum thriller that outstayed its welcome by at least an hour.

It’s no small achievement when a horror movie conjures palpable fear from thin air. Call “The Happening” a triumph of dis-ease.

Foreign film alert.

You won’t see “Reprise” in the local multiplex, but it’s worth a trip to the art theater or a place in your Netflix queue. It’s the first film of a young Danish filmmaker, Joachim Trier, and for those who crave the spirit of Truffaut or Godard, this will be a great pleasure.

Two young men send their first novels off to be published, dreaming of literary fame, success, and girls. One makes it right away, the other doesn’t. The movie follows their troubled friendship with gusto and energy. The filmmaking is so eclectic it may lose you from time to time, but there are enough pauses for you to regain your footing. Even when the characters take themselves too seriously the filmmaker knows better. Where so many films about being young sink in their own bathos, this one soars.