This is the third in the Matt Damon vehicles based on the Ludlum novels, none of which I recall reading (doesn't mean I haven't, though). Bourne's looking for clues as to how he became who he is, and naturally people keep dying just before he gets the full story, but not before he gets the next clue.
There's some nice fight sequences which are largely made incomprehensible by faux-documentary camera work, and the car chase (tick) suffers the same fate. There are some very silly security issues concerning a supposedly secret CIA office, and there's a stunningly small amount of acting visible on-screen; neither Damon nor female lead Julia Stiles move their faces, apart from one smile from Stiles in the epilogue. And there's a shifty CIA suit who looks disturbingly like Chris Langham. The movie suffers from lack of coherence concerning Stiles' character's relationship to Bourne, but it's entertaining nonsense all the same. The most enjoyable parts of the film are when the script writers can be bothered to show Bourne being, y'know, good at his job (see the opening sequences in Waterloo Station), rather than just skipping over him doing it at all and going directly to the results (the aforementioned security issues), and the ending leaves a lot to be desired. But I liked it anyway.