Duplicity, Tony Gilroy, 124 mins, 12A

I'm usually suspicious of films that try to persuade you before they've even started that you're in for something sleek, sophisticated and adult – so how could I not be wary of one entitled Duplicity? But it's just as well that we go into Tony Gilroy's comedy-thriller with our guard up. A good con trick often warns you in advance that you stand to get conned: you're so busy looking over your shoulder that you don't see the con when it comes, from right under your eyes.

Duplicity, it turns out, earns its title. Writer-director Gilroy pulled an ingenious bit of business in the final scenes of his corporate thriller Michael Clayton, and obviously enjoyed that so much that he's decided to go full out with the deviousness in his very differently toned follow-up. Julia Roberts and Clive Owen play corporate spies, constantly at odds and outwitting each other – or in love and secretly working together. We have to figure out which – and so, for that matter, do they. Claire and Ray are former CIA and MI6 operatives respectively, now working privately for rival multinationals in the cosmetics industry. Claire works for ruthless CEO Howard Tully (Tom Wilkinson), while Ray is with the company run by Tully's mortal rival Dick Garsik (a sublimely obnoxious Paul Giamatti). But wait – Claire is also a mole working for Garsik, alongside Ray. Still, that doesn't stop the lovers from doing the dirty on each other all the time – unless they're just doing it for the sake of appearances.

Gilroy works the elements of thriller and adult romcom up to a fine foam of paranoia, with the couple's relationship, professional as well as amorous, always coloured by mutual suspicion. They can't spend three passionate days in the sack without wondering whether each is trying to make the other miss his or her plane. In a hyper-luxurious hotel room with Ray, Claire says, "Can you imagine living like this? How much fun we'd have" – and your heart rather sinks as you think of the life of anxiety they have ahead of them.

Gilroy has built up a fabulously tricksy house-of-cards structure. The action keeps lapsing into globe-trotting flashbacks that become a running joke: "Rome, two years earlier..."; "London, 18 months ago...", "Miami, 12 months ago" – and then, with magnificent bathos, "Cleveland, three months ago", where Ray, out to conquer the world, has landed himself a job with ... a pizza company.

The prize everyone wants is a secret product that Tully has announced, and that will blow the cosmetics trade apart. (Gilroy actually delivers: the holy grail turns out to be something simple, eminently marketable and utterly impossible.) But Gilroy's great trick is to keep us out of the loop consistently: just when Garsik finally learns what his arch-rival is up to, we miss it, because the camera is off with Ray, ordering pizzas.

I'm not convinced, though, about the film's star pairing. Clive Owen is on good form, more comfortable than in the superficially similar The International, where he had to run around Europe looking aggrieved and never changing his shirt. Here he looks happier pulling the old suave jet-setting Brit-about-town routine – I'm thinking not so much of 007 as of Cary Grant in the 1963 spy lark Charade. Yet he manages to embody both alpha dog and slow puppy: you can believe his Ray would consider it a smart move to sign up with a pizza company.

In his saggy blokeishness, Owen impresses on you that he actually has a body weight. Roberts, on the other hand, is all bones and aura. There's little left of the vivaciously plastic Hollywood Sweetheart: her face is now as taut as Dietrich, set in a hard-as-platinum mask. This is fine when she's playing the icy operator, as when Claire directs a priceless basilisk glare at an office worker (a scene-stealing turn by Carrie Preston) who's got too friendly with Ray. But when Claire tells Ray she loves him, you can't buy it for a minute: you can't really envisage these two loving each other so much as enjoying the thrill of mutual suspicion that's always bound to lead to bed. Still, you can imagine how hard Angelina Jolie, say, would have worked to impress on you what a sophisticated time she's having: in a peculiar way, Roberts's detached efficiency tends to keep the thriller wheels well oiled.

Some viewers might baulk at a film quite so knowing, and the way Gilroy shuffles his scenes, even recycles whole swathes of dialogue, takes con-movie legerdemain to outrageous extremes: he's like a conjuror constantly revealing the insides of his sleeves, while trying to convince us that he's not actually wearing sleeves in the first place. There's a line in here – from Wilkinson's mogul, on the chemistry of cosmetics – that presumably serves as Gilroy's credo on writing and directing: "The placement of a single molecule can make the difference between triumph and catastrophe." It's not true, of course – there are some rogue molecules here, such as the over-insistent good-timey score and the smartypants Thomas Crown-style split-screens, and the film still works a treat. Duplicity pulls its precision-crafted rugs out from under us, one after another, and it's a gratifying, even luxurious, feeling.