Wedded blitz

Apparently there's great mystery concerning relations between Brad Pitt and Angelina Jolie. Are they in love? Inquiring minds want to know, and until somebody in that relationship pounces on Oprah's Winfrey's couch with besotted confirmation, we may never.

In the meantime, there's ''Mr. & Mrs. Smith," a painfully incoherent action-comedy starring Brad and Angelina -- that's ''Brangelina" to you US Weekly readers -- as John and Jane Smith, a couple whose marriage has gone stale from years of deception. He's an assassin. So is she. And, impossibly, neither one knows about the other's day job. When John and Jane are assigned to take out the same target, he botches her job (or is it she who botches his?), and each vows to annihilate whoever it was who cost them the kill. The movie wrings droplets of fun from the fact that hunter and hunted share the same driveway, and inevitably, many shots are fired and many more things blow up.

Maybe my priorities are wrong, but this inquiring mind wants to know when these two will find a movie entirely worthy of his understatement and her naughtiness. This one has its moments, but it's also littered with action-flick junk.

The idea of marriage and the suburbs as dead zones where the young and sexy go to rot is well taken and sometimes funny. There's also a nice chase sequence in which a family minivan is driven as though it were something in ''The Matrix," while John and Jane confess their lies to each other. (She admits that she hired actors to play her parents at the wedding.) Otherwise, the movie doesn't do enough to develop the hassles of being an assassin while being a spouse.

Screenwriter Simon Kinberg and director Doug Liman are playing with a high-concept conceit -- the best way to save a blah marriage is to turn the couple into action figures -- but the movie just isn't all that diverting as an exercise in spy versus spy. The action sequences work only when successfully married (sorry) to comedy, so the Smiths are entertaining as long as they're verbally sparring. After a shootout, one Smith says, ''I missed you." The other says, ''I missed you, too."

For their parts, Pitt and Jolie are up to the task. Admittedly, it's not a terribly tall one -- Brad, sweetie, can you hold up the shoulder-mounted missile launcher and look scrumptious? Thanks -- and they're loose and fun together. But I'm getting weary of watching stars flee explosions, throw knives, and be indestructible. Are there no actual human beings left in Hollywood? Is everyone a superhero? With Jolie, it doesn't even seem like acting anymore. She's one overblown action-adventure away from becoming Chuck Norris. Next to her, Pitt looks like the minx.

The physical fights between them turn inane because you never believe they dislike each other enough to justify it. Pitt and Jolie are the rare actors who have real chemistry (they both seem a little crazy), but the movie frequently misuses it. Kinberg and Liman revel in the Smiths' unnecessary roughness, not their banter.

The rest of the cast -- which (barely) includes the lovely Kerry Washington and Adam Brody, the chic geek of ''The O.C." -- is criminally underused. Angela Bassett is the voice of John's boss, but she herself never actually appears. Neither does Keith David, who provides the voice of Jane's boss. Maybe they're better off. Vince Vaughn shows up too, playing John's manically pathetic partner. He's a hoot, but he also seems to be acting in a completely different movie.

Vaughn's presence is a reminder of what a nagging patchwork this film is -- imagine Liman's ''Swingers" (which also starred Vaughn) hammered into his ''Bourne Identity." ''Mr. & Mrs. Smith" is several films engineered to resemble one, with Liman veering from screwball to speaker-busting blockbuster to mean-spirited farce without much finesse. It evokes the conjugal animus that drove Danny DeVito's ''The War of the Roses" in 1989, but that movie was crisp, focused, and bleakly funny. This one is not.

''Mr. & Mrs. Smith" bears a vague resemblance to a 1941 Alfred Hitchcock screwball of the same name. The film was about a couple, played by Robert Montgomery and Carole Lombard, who discover their marriage is a sham. One of their marital agreements involves asking each other one question a day that must be answered honestly. This version, despite the occasional banter, is a movie of painfully few words. Initially, the Smiths don't converse for fear of actually saying something true. And in this respect, art imitates Brangelina.

Wesley Morris can be reached at wmorris@globe.com.