Derek Cianfrance’s “The Place Beyond the Pines” is a handsomely mounted epic that at times sinks under the weight of its own ambition.

The story is three-fold. It begins with a motorcycle stunt driver named Luke (Ryan Gosling) who discovers that he has a son with an old flame (Eva Mendes) and turns to robbing banks to provide for the child. Eventually, the narrative finds Avery, a police officer (Bradley Cooper) who becomes embroiled in a police corruption case after pursing Luke. Finally, the story expands its scope a third time, studying how the two men’s decisions have reverberated across many years.

It’s not that Cianfrance has bitten off more than he can chew — the script is solid for the entire two-hour-and-20-minute running time — but like many anthology films, not every section is as compelling as its counterparts. The first part is the best, exploring Luke’s emotional upheaval and mission to become a paternal influence. Here the story feels immediate and authentic, akin to Gosling and Michelle William’s doomed romance in Cianfrance’s previous film, “Blue Valentine.” Even when he turns to robbing banks, Luke’s actions are believable for an addle vagabond who had no father of his own.

The problem is that when the film shifts its focus to Avery, it loses its intimate focus and devolves into rote plotting about an idealistic rookie cop fighting a corrupt police force. The themes of morality, justice and fatherhood still resonate in this portion, but the genre doldrums are enough to make it feel like a lesser companion piece that no one asked for. The last section thankfully returns to unmarked territory, but a third change in the cast of characters is just another reminder of how far the film has strayed from its terrific opening section.

Despite the unwieldy narrative, the film impresses in many regards. Gosling excels as an artificial symbol of masculinity whose layers are gradually peeled away, Mendes gives an impressively weathered performance as her character fights against upended circumstances, and Cooper seems tailor-made to be a guilt-ridden upstart. Another star of the show is Sean Bobbit ‘s cinematography, which aptly moves from chaotic police chases to serene countryside revelations and couldn’t be more flattering to Gosling’s physical attributes or his vulnerabilities. There is a standout scene where Luke weeps in a church and his tears are highlighted against a stained-glass window, suggesting that both Bobbit and Cianfrance could become more expressionistic auteurs if they are ever inclined.

The film would be a total package if Cianfrance were more modest or more aware of his story’s strengths. In an odd congruence with the movie’s themes, everything that went wrong here seems to be the result of one bad idea.

The Place Beyond the Pines (Cianfrance, 2013) B-

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