The Bourne Legacy (PG-13) ★★

Do the Bourne movies make any sense? Enough. The first three films — The Bourne Identity, Supremacy, and Ultimatum — throw in just enough detail into the covert ops babble and high-speed action that, by the end, Jason Bourne comes out an emotional character with an evident mission. That's where Bourne Legacy drops the ball. A ''sidequel'' to the original trilogy, Legacy follows super soldier Aaron Cross (Jeremy Renner) as he runs, jumps, and shoots his way out of the hands of his government captors. The film is identical to its predecessors; political intrigue, chase scenes, morally ambiguous CIA agents monitoring their man-on-the-run from a computer-filled HQ — a Bourne movie through and through. But Legacy has to dig deeper to find new ground to cover, introducing elements of sci-fi into the equation. The result is surprisingly limp and even more incomprehensible.

Damon's Bourne spent three blockbusters uncovering his past, erased by the assassin training program Treadstone. Renner's Alex Cross has a similar do-or-die mission: after Bourne's antics send Washington into a tizzy, Cross' own training program, Outcome, is terminated. Unlike Bourne, Cross is enhanced by ''chems'' (essentially steroid drugs) that keep him alive and kicking ass. When Outcome is ended, Cross goes rogue to stay alive and find more pills.

Steeped heavily in the plot lines of the established mythology, Bourne Legacy jumps back and forth between Cross and the clean up job of the movie's big bad (Edward Norton) and his elite squad of suits. The movie balances a lot of moving parts, but the adventure never feels sprawling or all that exciting. Actress Rachel Weisz, vibrant in nearly every role she takes on, plays a chemist who is key to Cross' chemical woes. The two are forced into partnership, Weisz limited to screaming, cowering, and sneaking past the occasional airport x-ray machine while her partner aggressively fistfights his way through any hurdle in his path. Renner is equally underserved. Cross is tailored to the actor's strengths — a darker, more aggressive character than Damon's Bourne, but with one out of every five of the character's lines being ''CHEMS!'' shouted at the top of his lungs, Renner never has the time or the material to develop him.

Writer/director Tony Gilroy (Michael Clayton, Duplicity, and the screenwriter of the previous three movies) is a master of dense language, but his style choices can't breath life into the 21st century epic speak. In the film's necessary car chase, Gilroy mimics the loose camera style of Ultimatum director Paul Greengrass without fully embracing it. The wishy washy approach sucks the life out of large-scale set pieces. The final 30 minutes of Bourne Legacy is a shaky cam naysayer's worst nightmare.

The Bourne Legacy demonstrates potential without ever kicking into high gear. One scene, when Gilroy finally slows down and unleashes absolute terror on screen, is striking. Unfortunately, the moment doesn't involve our hero and its implications never explained. That sums up Legacy; by the film's conclusion, it only feels like the first hour has played out. The movie crawls — which would be much more forgivable if the intense banter between its large ensemble carried weight. Instead, Legacy packs the thrills of an airport thriller: sporadically entertaining and instantly forgettable.

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Hollywood.com rated this film 2 stars.