From the deep-fat fryer of tabloid publicity surrounding Brad Pitt and Angelina Jolie, the are-they-or-aren’t-they stars of Mr. and Mrs. Smith, it could be expected that the movie be a greasy, leaden meal.

Instead, it’s a stupid-but-solid summer soufflé about marital discord between assassins that gets whipped up by the madcap momentum of comedy, action and composer John Powell’s inventively orchestrated score.

The film opens with John (Pitt) and Jane (Jolie) visiting a marriage counselor who sounds strangely like David Carradine. If you think choosing him as a marriage healer seems dangerous, try their professions — assassins working for the high-paying powers that be.

But professional courtesy dictates that neither knows what the other does, and oh how the marriage has suffered for it. The courtship by tequila and sexy dancing in the rain is long ago, and the introduction of peas into the evening meal is what passes for table talk.

Things are humorously blah until the Smiths are accidentally double-booked for an assignment. Somewhere, it’s written in the assassin code that they each have 48 hours to wipe out the other before they become easily expendable liabilities to their employers.

After a somewhat repetitive start, the movie zooms to life at that point with a suspenseful dinnertime set piece where every table setting becomes a possible weapon, every dish a possible trap. The scene moves with the same sly bounce of the jazzy score that accompanies it.

Like any movie with a mega-budget, Mr. and Mrs. Smith feels compelled to throw computer-generated trickery on the screen. And as Jane slides from one skyscraper to another via a high wire, its graininess is laughably phony.

But the movie relies instead on Pitt’s always-plotting eye gleam, Jolie’s viper-like toughness, clever quips, smoothly edited fight sequences and brief bits from the always-reliable Vince Vaughn (as John’s hitman buddy, Eddie). It’s all dumb fun enough to carry the movie through its occasionally lame patches.

That includes weak attempts at symbolism (with nondescript names like John and Jane Smith, why this husband and wife could be the Everycouple!), the last-act “twist” that’s obvious from the first moment Seth from The O.C. wanders onscreen and a climactic gunfight in a home-furnishings store that’s a misfire. (Exactly how good an assassin could Jane really be if she bares her midriff beneath all that bulletproof armor?)

Who knows about Pitt and Jolie’s offscreen relationship? Aside from Jennifer Aniston, who should really care? Onscreen, the pair boils over when and where it counts.

Much of their chemistry is channeled into the numerous, pretty-raw-for-a-PG-13 hand-to-hand beatdowns traded between them. The movie fully capitalizes on the couples’ competitive toughness in a fight scene that shows the hard way to home renovation. It’s a testament to director Doug Liman’s blend of styles that a tender morning-after breakfast in the demolished kitchen follows this very violent foreplay.

The real climax of Mr. and Mrs. Smith should be a furious minivan chase on the interstate in which the couple’s long-buried secrets fly out along with the bullets. The tired gunfight that closes out the movie is nothing compared to this demolition derby dazzler set to, of all things, Air Supply’s “Making Love Out of Nothing At All.”

Sure, this dish falls from its frothy level of fun a little bit in the end, but it’s only under the thudding crash of its anticlimactic ending and not the baggage of its lead performers.