One of the pleasures of reviewing films - of reviewing any art form, for that matter - is the excitement of coming upon a work that reaches beyond the conventional, that challenges us to join it on its own terms, that succeeds in expanding our notions of 'proper' art and leaves us somehow enlarged ourselves. That's how I feel about "Syriana," the bold and uncompromising film written and directed by Stephen Gaghan, based in part on the memoir of a CIA agent named Robert Baer, that takes us through the fragmented and interlocking worlds of international oil, politics, money and, of course, greed.

In a sense "Syriana" is a film without a plot; that is, it is stuffed so full of simultaneous plots and plans and acts that it comes at us as a collage, an assemblage of offhand conversations, barely spoken agreements, nods and moments that are as likely to be duplicitous and deadly as anything shouted or staged in a conventional shoot-em-up. The film begins as a major Texas oil company, Connex, loses out on oil exploration rights in Kazakhstan to another, tiny company, Killen, but instantly merges with Killen. Why? Well, there's an oil sale to China involved, along with United States rules about bribing officials of other countries. At the same time an aging CIA agent, Bob Barnes (George Clooney), is being hung out to dry by his bosses at Langley. And an American financial consultant in Geneva, Bryan Woodman (Matt Damon), is working with a Persian Gulf emir to provide him with new revenue sources.

Now we're still only halfway there in understanding "Syriana," because there are a few other tracks to follow. One deals with the intricacies of the Connex merger, another with two Pakistani guest workers in the Persian Gulf who are unceremoniously told they are no longer wanted and turn to a madrasa for consolation and, for one, a possible Muslim martyrdom. There is a horrifying moment for Woodman when, at a party in the emir's palace-like second home in Spain, his young son dies in an accident. The sheik offers Woodman's company a $100 million contract by way of reparation. "What will you give me for my other son?" asks Woodman. But he takes the money. And then there is the story of the emir's two sons, rivals for the throne. One wants to use the oil revenues to modernize his country, in order to strengthen it; the other son is backed by the United States because he will ensure that the emirate will remain a client state.

Gaghan weaves these threads in and out and around us for two hours; he is not interested in helping us find our way through the morass of interlocking stories but wants us to respond to the cumulative effect of the ways in which an essential but limited resource - oil - becomes the holy grail of international politics, business and finance. He's cast his film with an unerring eye: the heavy, sagging Clooney as the CIA agent; Chris Cooper as an oilman, Christopher Plummer as a Washington attorney who specializes in fixing broken deals, Amanda Peet as Woodman's wife, and previously unknown actors as the various Middle-east and Pakistani participants.

The film is not quite perfect; Gaghan might have chosen to give us a bit more closure to his stories, though perhaps that's just my own conventional response. But the power of each moment in "Syriana" is extraordinary, and that surely is more than enough to make this one of the finest films in ages.