The Bourne Ultimatum is the latest film by Paul Greengrass, whose previous two credits are United 93 and The Bourne Supremacy. Strangely, Greengrass didn't seem to see the difference in seriousness between a docudrama that essentially peels off a fresh scab and Matt Damon running and jumping through expensive explosions. The Greengrass treatment is the same in both instances: endless shaky-cam, no jokes. And while this might be appropriate for the expert dramatizations of United 93, there's something vaguely unnerving about a big-budget franchise movie that's equally but inexplicably self-serious.

The Bourne Supremacy was a passable time-waster, but three years later I can't remember anything about it, aside from wondering why the world's dullest spy was getting his own franchise. Part of the problem was probably buying the rights to a famous franchise only to discard pretty much everything but the premise: check out the Wikipedia page for Jason Bourne for more on the character’s originally conceived, Vietnam-era background. Universal bought a name, hollowed out the character, and forgot to fill it back up with something. Bourne is a disaster of a protagonist, as indestructible as the Terminator and every bit as humorless.

Fortunately, The Bourne Ultimatum is an improvement on its predecessor -- more concerned with the soothing sounds of screeching metal than the irritating chirping of one vacant character to another. Which isn't to say that when people start talking they aren't groan-inducing, they just don’t talk as much. In place of all that chatter, in fact, is the pointed critique of the Bush administration some partisans were hoping for in United 93. Be careful what you wish for: One of the film’s two main villains, CIA black-ops boss Noah Vosen (David Strathairn) announces it's not his fault a mission failed because there was so little time to prepare (failure to react in a timely fashion to news of plane crashes, check), proceeds to initiate situations in which innocent civilians are picked off while the real target stays safe and eventually snaps that he's going to keep fighting "until we win." Mission so totally not accomplished.

Like the low-fi, paranoiac post-Nixon '70s thrillers it resembles (any CGI here is practically invisible), The Bourne Ultimatum taps into fresh administration disillusionment for its portrait of a rogue government full of internal factions, overzealous creeps who monitor everything, and shadowy experimental torture divisions. Vosen duels with returning CIA good girl Pamela Landy (Joan Allen), attempting to kill off Bourne while she attempts to dig to the bottom of the conspiracy. As Bourne, Damon once again is laconic enough to make Clint Eastwood seem like Robin Williams. Ostensibly, he’s still seeking his true identity, but it’s hard to tell when the plot mimics that of the last two films -- Bourne visits a new country and kicks some fresh ass every 15 minutes, inexplicably stumbling upon clues to his past in the process. It's spy-movie piffle, same as it ever was, though slightly more credible for a more skeptical age: there is no amazing satellite technology to allow for overhead views from anywhere, but it almost makes sense that the government would track people's progress along Google Maps. (Like they could do better.)

Most of the dialogue in the CIA sections is merely serviceable, alternating between techno-gabble about pulling up coordinates and phone lines and Strathairn’s heavy-handed speeches. The action sequences, on the other hand, are first rate. Greengrass' taste for over-emphatic shaky-cam -- it goes beyond documentary mock-verisimilitude into the oddly abstract -- is way beyond self-parody at this point, but the fact that it jumbles spatial relations between characters into an incomprehensible mess turns out to not be much of a problem. In the many, suspenseful chases, Greengrass and editor Christopher Rouse make up for this chronic discombobulation with expert timing: you almost always grasp near-intuitively how long it takes to get from one place to another and how far apart people are. There are at least two stand-out sequences -- Bourne vs. Waterloo Station, Bourne vs. Tangiers -- almost as exhilarating as the dual-time car chase in Deja Vu (a k a the best action sequence in recent memory).

There's also a healthy sense of the absurd in the many, many wall-to-wall chases that gratifyingly make up the majority of the brisk, under-two-hours running time. When Damon unleashes his inner Steve McQueen to ride a motorcycle up and down outdoor stairs in Tangiers -- approximately the 17,000th location, the globe-trotting being another pleasing aspect of Ultimatum’s retro feel -- I realized I was having a fine old time. The flashbacks to Bourne’s unsurprising past are tedious and the hero still bland, but in an era of overwhelmingly self-important blockbusters, where every stunted superhero and would-be Tolkien epic seems to be suffering from clinical depression, The Bourne Ultimatum’s terse series of explosions and chases just about hits the spot. Characters are overrated.