"The Bourne Ultimatum" - the third and potentially final installment of the series based on the Robert Ludlum Cold War spy novels - picks up scant seconds after 2004's "The Bourne Supremacy" left off, with amnesiac assassin Jason Bourne shot and on the run from the Moscow police. To make matters worse, he's still haunted by the memory of his dead lover Marie (Franka Potente, sorely missed) and plagued by those nasty flashbacks - this time featuring someone who bears a striking resemblance to Albert Finney. Could this vision hold the key to Bourne's identity (at least more so than 2002's "The Bourne Identity" did)? Let's just say, if the filmmakers cast Albert Finney in the role, it's probably pretty important.

Of course, Bourne's identity has almost become secondary to this surprisingly sturdy but increasingly preposterous franchise. The fun of these movies is in watching Bourne - played again by Matt Damon, reigning king of the intense blank stare - get into and out of sticky situations, always staying one step ahead of the corrupt shadow agency that created - and seems bent on destroying - their superspy. Like "Supremacy", "Ultimatum" is effectively one long chase scene from beginning to end. Ever since Paul Greengrass took over from "Identity" director Doug Limon, the character's story has (happily) taken a backseat to the filmmaking itself. It's telling that there is precious little dialogue in "Ultimatum" (though the screenplay is credited to three writers: Tony Gilroy, Scott Z. Burns and George Nolfi). The story is told almost entirely visually.

Mr. Greengrass's camera, like his lead character, never stops moving. From Moscow to Turin to Madrid to London to New York City (with brief stops at Langley, of course), "Ultimatum" is one expertly-crafted but increasingly repetitious action sequence after another. A pitch-perfect opening - during which Bourne has to protect himself and a reporter via cell phone in London's crowded waterloo station - eventually leads to a protracted, almost pointless chase through and above Tangiers, and on and on. As exciting as Mr. Greengrass's direction is (he can even make a car chase through Manhattan seem new), eventually Bourne, like his audience, must get tired. And in the end, there's not much to distinguish "Ultimatum" from "Supremacy".

Bourne, again, is consistently one step ahead of every loyalty-challenged supporting player. Julia Stiles' character is shoehorned into the series yet again, though she does some of her best work this time around, becoming almost a partner in crime for Mr. Damon. Joan Allen winds herself up slightly less tightly this time around as Pamela Landy. Like everyone who comes in contact with Bourne, she begins to question her superiors - and who wouldn't with the likes of David Strathairn and Albert Finney running the place (in roles that would have been played by Chris Cooper and Brian Cox, had Bourne not disposed of them in previous films).

Like "Live Free of Die Hard", it's refreshing to see an old school spy thriller with practical, metal-crushing stunts (we'll ignore the harrier jet climax of "Live Free" for now), but the seams of this franchise are beginning to show. Plot holes are leapt over with reckless abandon, characters behave exactly as they need to with little motivation, and Bourne, it seems, is made of steel (at the very least, he could use a tetanus shot). It's unclear what the "Ultimatum" is in the film (not that I know why the last one was a "Supremacy" either), but if this isn't the last installment in the series, we might need some downtime before we see Bourne again.