Joseph Gordon-Leavitt in "Looper."
Joseph Gordon-Leavitt in "Looper."

Rian Johnson first made a mark with his remarkable 2005 debut "Brick," a dark high school fantasy that toyed with genre and fused the sensibilities of "Donnie Darko" with Raymond Chandler. His less successful followup, the playful caper flick "The Brothers Bloom," contained a similarly tricky narrative that took multiple unexpected turns. As Johnson demonstrated a clear penchant for the interplay between reality and fantasy, it makes sense that he would eventually enter the science-fiction realm.

"Looper," a rollicking dystopian action-adventure yarn about time travel, is a reasonable broadening of the filmmaker's scope with enough potential to make its flaws stand out. The first hour displays a brilliant elaboration on the noir antics demonstrated in "Brick," but the movie's later scenes stumble in a mass of half-formed ideas. Nevertheless, craftsmanship holds "Looper" together during its concluding moments so that the skill behind the camera remains in focus, resulting in an experience nearly as fragmented as the time-traveling antics at its center.

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Reteaming with "Brick" star Joseph Gordon-Levitt, Johnson has written the typically ebullient actor a dreary role with plenty of noir-inflected dialogue. Set in 2044, the story casts Gordon-Levitt as clandestine hitman Joe, part of a secretive group hired by employers from a future 30 years away, where time travel has been invented. With a workmanlike sense of calm, Joe routinely heads to a desolate area where veiled targets from the future abruptly appear on schedule. The job is chillingly simple: He pulls the trigger, collects his loot and calls it a day.

Having established his routine in a moody first-person voiceover, Joe tacks on the catch: At a certain point, the organization that hires loopers fires them by sending back their futures selves so that the younger killers can wipe them out. The imminent deadline means that most loopers have made peace with their limited time. "This job doesn't attract forward-thinking people," Joe deadpans, although he has enough cunning to plot a means of capitalizing on his limited time: Studying up on his French, Joe hopes to cash out spend his later years exploring Europe.

A soulful character looking to get out, Joe faces a classic struggle that's not nearly as impressive as the world Johnson constructs to surround his creation. With small touches -- a flying car here, a nifty technical device there -- "Looper" makes its dark near future into a palpable reality replete with a struggling impoverished class that makes the latest recession look like downright pedestrian.

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Joe isn't invulnerable to the hard times: Addicted to a nameless futuristic narcotic that takes the form of eyedrops, he wanders through the weary cycle of his profession in a daze. Johnson also crafts a series of colorful coworkers, including Paul Dano in a fleeting but enjoyably high energy turn and a looper boss played by Jeff Daniels. Characteristically frumpy, Daniels' performance is an unconventional choice for a menacing bad guy, but he's competent enough until a point where the movie basically forgets about him.

Naturally, the self-extermination responsibility that all loopers eventually face takes center stage, and the movie launches into its brisk plot. When Dano's character allows his older self to escape, the men learn that a murky new future boss named The Rainmaker has issued a mandate to execute all existing loopers. Unfazed, Joe keeps his head down until his own future self (Bruce Willis) shows up and knocks the younger Joe unconscious before he can pull the trigger.

A clever twist on the chase movie ensues with multiple layers of narrative unfolding at once: A swift montage explores Joe's life over the course of a three-decade period, with an artful, wordless explanation for his decision to rebel against the contract. Having fallen for the woman of his dreams, Joe decides the only way to keep his life with her is to travel back to 2044 and kill The Rainmaker in his youth. Meanwhile, the younger Joe still just wants to do his job. Establishing dueling stakes cleverly arranged to keep our sympathies at bay, "Looper" launches into its final act.