If Clive Owen had taken over the role of James Bond, rather than Daniel Craig — who hasn't yet brought to it anything like the romantic flair that Owen could have — the result, with a lot of luck, might have been a movie like "Duplicity." This second feature by writer/director Tony Gilroy ("Michael Clayton") is devilishly complex and extravagantly funny. Owen and his co-star, Julia Roberts, playing a pair of scheming freelance spies, don't over-drive their star power, but their effortless, wisecracking chemistry lights up the picture. And the story is so clever that at the end even some of the characters aren't quite sure what's happened. Neither are we (until we've squinted back over it a bit), but we're too tickled to care.

CIA agent Claire Stenwick (Roberts) and Ray Koval (Owen), of Britain's MI6 (Bond's old outfit), have hooked up romantically and professionally and decided to "go private" — into the lucrative realm of corporate espionage — in order to score enough money to retire in the high-flying style to which they've become accustomed. (Claire figures $40 million should do it.) They don't really trust each other, and as the movie's brain-teasing pranks and double-crosses pile up, neither do we.

Ray and Claire have hired themselves out to a big soap-and-lotions corporation run by a ruthless mogul named Garsik (Paul Giamatti), who's at war with a rival outfit helmed by the slick, silken Tully (Tom Wilkinson). Claire has infiltrated Tully's operation and discovered that he's on the verge of a major commercial breakthrough — a game-changing product that'll reap tons of money. Garsik is determined to steal Tully's secret formula for whatever this damn concoction is and do the reaping himself. Ray and Claire are on hand to help — or are they? Also in the mix is Garsik's crack backup team, led by a wily operative named Duke (Denis O'Hare), as well as a slob-genius chemist named Ronny (Christopher Denham) and a winsome travel agent named Barbara (Carrie Preston, walking away with one of the movie's many hilarious scenes). You can't imagine how complicated all of this gets.

Like the Bond films, and the "Bourne" movies, too (Gilroy was a key writer on all three of those), "Duplicity" logs extensive flight time, touching down everywhere from Dubai and the Bahamas to London, Rome and Zurich, with brief layovers in Miami (where we learn a bit about the unexpected espionage opportunities in the frozen-pizza industry) and, uh, Cleveland. The dialogue is so smart and snappy, it'd be wrong to reproduce any of it at length. Let us only note that when Claire accuses Ray of having seduced a female target, his wounded reply is "That's my cover."

The picture has a unity of wit and structure that could only have been achieved by a very sharp writer who's also a gifted filmmaker. (One with excellent taste in collaborators, too — you could put your brain on snooze and have a perfectly fine time savoring the rich color and elegant camera moves of cinematographer Robert Elswit, one of several "Michael Clayton" alumni who worked on the picture.) Apart from the dazzling plot choreography, one of Gilroy's smartest strategies was to allow Roberts to dial down her all-devouring smile in favor of a more deadpan, reactive performance, allowing Owen's warm comedic agility to take wing. Are Ray and Claire really in love, or just in league? We're never entirely sure. "I think about you all the time," he declares, in a moment of possible passion. "I think about you even when you're with me."

Don't miss Kurt Loder's reviews of "I Love You, Man" and "Knowing," also new in theaters this week.

Check out everything we've got on "Duplicity."

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