The immensely exciting Bourne trilogy, culled from Robert Ludlum’s best sellers, builds to a satisfying conclusion in The Bourne Ultimatum, which ties together the arcs of The Bourne Identity (in which amnesiac CIA “black ops” agent Jason Bourne attempts to find out who he is) and The Bourne Supremacy (about his drive to track down the CIA higher-up responsible for murdering his girlfriend, Marie Kreutz). In Ultimatum, Bourne (Matt Damon), still haunted by Marie’s death, reads about himself in a column by an English journalist named Simon Ross (Paddy Considine) and tracks Ross down to find out who his source was. Bourne’s reappearance puts him back on the CIA radar.

Supremacy ended with the defeat of the man who generated the program that turned Bourne into a killing machine. But there’s an apparently bottomless supply of such villains. This time around, CIA deputy director Noah Vosen (David Strathairn) targets not only Bourne but Ross’s source, Neal Daniels (Colin Stanton), who runs the Tangier office, and Nicky Parsons (Julia Stiles—a welcome face from the last picture), who has been transferred to Daniels’s staff and volunteers her help when Bourne shows up.

Once more the only CIA executive with any sense of morality is Pam Landy (Joan Allen), whose humanism keeps her firmly on Bourne’s side. When Landy objects to Vosen’s sending an assassin after Parsons, Vosen replies coolly that he has the mandate to pick off anyone he sees fit to and that he intends to keep eliminating threats to national security until “we” win. The filmmakers—director Paul Greengrass and screenwriters Tony Gilroy, Scott Z. Burns and George Nolfi—present Vosen’s arrogance and self-righteousness as an obvious critique of the insulation and unassailable confidence of the Bush White House. (In playing the doctor whose behavioral experimentation altered Bourne’s original personality, Albert Finney evokes Donald Rumsfeld’s vocal idiosyncrasies.)

This view of government is now as standard in certain kinds of action pictures as paranoia about government and corporations was in 1970s thrillers like The Parallax View and Three Days of the Condor.

Though the politics of Ultimatum gives it a certain bite and savvy, the focus of the movie is not politics but the dazzlingly complex and gripping action scenes. The movie takes off with a sequence at Waterloo Station—chosen by Bourne as a meeting place because it’s so busy—where Bourne guides Ross deftly through the London crowds via cell phone so that Vosen’s hit men are continually faked out. Much of the pleasure of the Bourne movies has always been the wit with which Bourne runs circles around his pursuers, which is expressed in the wizardry of Greengrass’s direction as well as in the dry humor of Damon’s “Gotcha!” communications with the CIA bosses.

Ultimatum isn’t deep, but it has a couple of moments that suggest unexpected reserves of feeling. Both involve Stiles, a remarkably economical actress who can flood the briefest interlude with emotion while retaining her trademark crispness and physical alertness. At one point, when Parsons realizes that she too is on a hit list, you can practically see her heart quicken. When she has to go on the run, she cuts and dyes her hair in the style that Kreutz (Franka Potente) chose when she became a fugitive in Identity. When Bourne looks at her, just a moment’s pause tells us what he’s remembering.

The pulse of the Bourne movies is a man’s struggle to rediscover the humanity that his handlers hoped to have drained out of him. That’s why the films have to have a human face. Greengrass, who combines astonishing visual skills with an instinct for coaching actors, is the ideal director to supply it. His use of the hand-held camera and multiple points of view in Ultimatum, in tandem with the rapid editing, gives the movie a shimmering, crystalline look, especially when the screen approximates the long-buried images from Bourne’s past, which come to him in the form of piercing shards of memory. The Bourne Ultimatum is both a first-rate thriller and a thrilling example of what a filmmaker can do.