Duplicity director-writer Tony Gilroy “loves puzzles,” writes New Yorker profiler D.T. Max, “and Michael Clayton was full of them. So is Duplicity (3.20), with its scheming, warily passionate spies.

“‘If I told you I loved you, would it make any difference?’ Claire (Julia Roberts) asks Ray (Clive Owen) at one point. ‘If you told me or if I believed you?’ Ray responds. Gilroy calls the film ‘counterprogramming — not the normal thing to do next.’ It is fast, lighthearted, and intense. Even though, as Gilroy explains, ‘Michael Clayton could have been a novel [but]Duplicity could only exist as a movie.”

“Yet it, too, is out of step with current Hollywood practice,” Max observes. “It is a thriller shot almost entirely indoors. Ray and Claire do not career through Rome in a Porsche. There are no police cruisers piling up behind them at the end. Their passion is communicated largely with faces, not bodies.

“The engine of Duplicity is the question of who is tricking whom — and, thus, where reality lies. The movie has an array of flashbacks that scramble the time frame, a complication that almost prevented the film from being made. Steven Spielberg, who, at one point, was interested in directing it, with Tom Cruise in the Owen role, was so confused by the plot that he organized a table reading in his office at DreamWorks to clarify who did what to whom. Later, he jokingly suggested that the DVD include, as a bonus track, a chronological run-through of the story. (Ultimately, he dropped out.)

“The core of Duplicity is the screenwriting trope known as the reversal. Gilroy told me, ‘A reversal is just anything that’s a surprise. It’s a way of keeping the audience interested.” A camera follows a man as he goes up the stairs to an apartment; we see his wedding ring as he pulls out his keys. He pushes open the door, slowly — a husband coming home, trudging up the stairs with his briefcase. But a woman in black lingerie greets him: he’s seeing his mistress! That is a reversal. In Good Will Hunting, when Matt Damon, mopping the floor at a university, comes upon a complicated math problem on a blackboard and solves it, the audience suddenly realizes that he is not an ordinary janitor — that’s a reversal, too.

Duplicity is so crammed with reversals that Stephen Schiff, a screenwriter who is a friend of Gilroy’s, says that the story ‘achieves a kind of meta quality.'”

All I can say is, I’m very glad I have a copy of the script in my script folder. I’m going to read it over sometime between now and the N.Y. premiere, and when I see Duplicity a second time I’m going to be with it all the more. (Not to say I wasn’t with it the first time, but it made me feel a little dumb.) Which I’m very much looking forward to.