The Adjustment Bureau may have put so much time and energy into the star-studded cameos that open the film that it forgot to pay attention to the real meat of the matter. This conceptual thriller, a kind of meat-and-potatoes, clunkier brain twister in the Inception-mode, centers on ambitious senatorial candidate David Norris (Matt Damon), an authentic, no-bullshit politician who has risen to the ranks of beloved working-class hero.

Things start off pretty shaky with TAB's proposition that David has blown his chances at the Senate seat with the revelation that he engaged in the fratboy prank of "mooning" in his wilder days. With governors running off to Argentina for dalliances with their mistresses, is this the best writer and director George Nolfi can do to legitimize the political destruction of this local son?

With his Senate hopes dashed, David returns to civilian life. He's obsessed with the gorgeous free-spirit and avant-garde dancer Elise Sellas (Emily Blunt), whom he met the night of his Senate concession speech. Elise represents a crossroads in David's life. If he pursues her, he gives up his political ambitions. If he returns to politics without her, he runs the risk of being emotionally unfulfilled.

David has unknowingly stumbled upon a vast conspiracy run by Mad Men guys in gray flannel suits, including Mad Men's John Slattery. Slattery is one of the minions in The Adjustment Bureau, a secret subculture of men led by Thompson (Terence Stamp), whose job it is to keep human beings on fate's proper course.

The Adjustment Bureau keeps a library of books filled with the life path of each human being in its care. It seems that, at one time, people were graced with free will, but events such as two world wars convinced the adjustors that humans couldn't handle that kind of freedom. Now, they plot out humanity's every move and leap into action when David veers from his path in order to pursue Elise. Teenagers in love with meddling parents haven't advocated so hard or so longingly to be together as this star-crossed couple.

Nolfi creates a world that operates by its own internal logic, but it's a tediously explained, relatively boring logic centered on magic hats and a point made early on (you wait for the plot to circle back to it): The bureau cannot operate effectively in the rain. A film based on a short story, "Adjustment Team" by Philip K Dick, TAB raises the intriguing notion of how we define happiness in our lives. Is a satisfying existence measured by personal contentment or professional success? It's a compelling idea, but poorly executed here.

At every turn, TAB makes one aware of the thin line in fantasy, separating a great story that carries one along and a shaky plot whose shoddy workmanship makes being carried along nearly impossible. Even the goofiest plot line can beguile us if great writing, acting, special effects and a lightning pace keep those doubts of "could this really happen?" at bay. But TAB is far too complicated in explaining the where and why of its tangled plot to have us suspending disbelief for long.