Early in 2007's Oscar season, Tony Gilroy - then best known as the writer of all three Jason Bourne movies - made his directorial debut with Michael Clayton, a sober-minded, unexceptional and very well-crafted thriller with pretensions to social commentary about the evils done by corporations in the name of profit; its reward for this seriousness and craftsmanship was a somewhat-unexpected cache of Academy Award nominations. Lately, he has released Duplicity, another thriller set in much the same environment and with the same thematic concerns: it is not remotely as serious and thus will not have the same success with awards-granting tastemakers, although for the same reason it is a great deal more fun to watch, and by my accounting, it's actually quite a bit better.

The plot, in the abstract: Ray Koval (Clive Owen) has just been hired by one of the two largest health and beauty manufacturers to work on their corporate espionage team, specifically to serve as the contact person for Claire Stenwick (Julia Roberts), the company's mole high inside the counterintelligence team for the other of the two largest health and beauty manufacturers. The problem for both, it would seem, is that they have a tarnished history: five years earlier, in the summer of 2003, they crossed paths in Dubai, when Ray was working with MI6 and Claire with the C.I.A., and she was tasked with stealing some documents from him under pretense of seducing him. Except that this isn't quite the issue that it looks like, for as we learn in flashback, Ray and Claire first met again in Rome in 2006, fell madly in love, and started to hatch a giant con that would end up profiting them somewhere in the neighborhood of $40 million, and their mutual employment is apparently the result of that conspiracy.

I shan't give away another word of what happens, because a big part of the fun in Duplicity - though not all of it, nor even the biggest part - is in keeping up with the impenetrable nest of potential double-crosses that Ray and Claire inflict upon one another in the course of 24 months leading up to their great present-day scheme. I say "potential double-crosses", because it's never altogether clear whether the couple is working together or against one another, and this brings us to what I'd happily call the film's most original and pleasing personality quirk.

Duplicity is a film with two hearts: obviously, it is a top-notch twisty caper about two smart, well-trained people executing a massive long con, and less-obviously, it is a marvelously bent romantic comedy about two utterly fucked-up people. In every one of the film's flashbacks - themselves a marvel of story structure, rigidly plopped into the narrative in exactly the places where they'll have the biggest possible impact - Ray and Claire have a nearly identical conversation in which they accuse each other of lying and treachery. The point of these scenes, we intuitively understand, isn't that the lovers have been ruined for human contact because of their personal histories; rather that because of their histories, they've been perfectly conditioned to love the only other person in the world who's equally paranoid about every little gesture and word choice. Betrayal and deception aren't the signs of an unhealthy relationship here, but the basis for all the eroticism between the two. I am reminded of Ernst Lubitsch's majestic comedy Trouble in Paradise, one of the most sexually mature romances in film history, where Miriam Hopkins and Herbert Marshall play a pair of society thieves who fall in love precisely because of the excitement of knowing that the the other person is always planning on cheating them out of everything.

Given two such diabolically twisted characters, Owens and Roberts produce one of the most witty and satisfying pair of lovers I've seen in a movie in ages, feeling every inch like they've just stepped out of a 1930s screwball comedy. Both of them give their best performance in a long time; Roberts in particular hasn't been even close to this good since Erin Brockovich in 2000, and it's almost indecently pleasurable to see her trade in her worn-out All-American Cute Thing persona for a character who uses exactly that persona as a tactical weapon. Much of the appeal of Duplicity is the simple and undeniable delight of seeing two actors with tremendous chemistry playing off of each other with such wicked zestiness.

And much of the appeal is that Gilroy, having proven himself a fine filmmaker, now gets to show off by injecting every last scrap of manic energy he can spare into a sparkling, cheerfully shallow entertainment (for a start, Duplicity is by far the most playful thing he's ever written). The film starts out with all guns firing in its second scene, in which the two competing CEOs - Howard Tully (Tom Wilkinson) and Richard Garsik (Paul Giamatti) - storm across a rainy airstrip and starting wailing on each other as their associated staff members look on nervously. It's done in slow-motion while James Newton Howard's sly, peppy score burbles on underneath, and it's one of the most energetic scenes I've encounted in a movie in what feels like ages; from the joke of two respectable men in suits pouncing at each other in lovingly-rendered detail, to the quieter jokes such as the line of spittle that Giamatti lets fly in endless slow-mo.

The rest of the film speeds up, such that if you blink you're probably going to miss some gag or reference or plot point, but it always holds on to the gaudy charm of that first scene. Where Michael Clayton was stately and cautious, Duplicity is balls-out, incorporating split-screen and sub-frames, weird camera angles and a chaotic blend of long takes and quick cutting; Gilroy seems to have thrown everything against the wall, to find that nearly everything sticks. None of this is Sensible or Subtle, but it's a blast, and I was certainly too dazzled to give a damn if it "meant" anything.

Gilroy's band of collaborators are all on their best games - master cinematographer Robert Elswit gets to move from gritty exteriors in present-day New York to glowing shots of a romanticised Europe to sterile corporate interiors, Gilroy's brother John edits the whole thing together with a lightning pace that never betrays coherence, and the above-mentioned Howard gives a score that seems at its best to have wandered in from one of those Euro-spy romps from the 1960s. Duplicity is all about the sizzle, with only a feint in the direction of relevance (corporations are venal, apparently), but the sizzle is absolutely magnificent. It's a perfectly-crafted espionage thriller married to the best throwback rom-com in years; I have no hesitation in stating that Duplicity is the very best film on this model since the 2001 Ocean's Eleven remake. The degree to which that is a recommendation and not a warning probably varies from viewer to viewer; me, I think it's one of the only completely great films of the young 2009.