More than two years after its debut at the Tribeca Film Festival, Griffin Dunne’s Fierce People has finally stumbled into theaters, and it’s not hard to understand the delay. For all its admirable qualities, it is a sprawling mess, ambitious in scope but too fatally flawed to make the profound, almost poetic statements it wants to make about the divide between the rich and the poor.

For one thing, it is a story muddled with too many ideas and too little screen time to accommodate them all. Halfway through the film, a sudden tonal shift leaves no doubt that the aura of fragile serenity enjoyed by Ogden C. Osborne (Donald Sutherland) at his Kennedy-esque compound in New Jersey is a front: Behind it lurks a clan ferociously ready to pounce on its own, or on any outsiders foolish enough to seek entry.

It is an analogy that fascinates screenwriter Dirk Wittenborn. Early and often, he compares the inner workings of the Osborne family, classic old-money aristocrats, with the rituals of the Ishkanani, a primal South American tribe that devours its members with ravenous abandon.

As a literary device, the metaphor may have worked in Wittenborn’s 2003 novel, but here it fails to resonate. And while his contempt for this particular group of pampered hedonists does not, he goes decidedly over the top when Bryce (Chris Evans, of Fantastic Four) completes a bizarre about-face from flamboyant trust-funder to psycho killer.

It is a jarring turn for a movie that seems to lack direction until enthusiastically stripping the Osbornes of their pompous airs and laying their darkest secrets bare. It’s an even harsher wake-up call for Liz (Diane Lane) and Finn (Anton Yelchin), a drug-addicted masseuse and her coming-of-age son who turn to Ogden in their direst hour, hoping (a bit naively) for generosity from an enigmatic friend. What they find instead is a family so corroded by money and power that it has descended to savagery.

An interesting idea, perhaps, but Fierce People is too scatterbrained and self-indulgent to deliver on the premise. There are subplots that go nowhere – Liz’s abbreviated romance with a blandly uninteresting doctor (Christopher Shyer), for instance – and key questions that remain unanswered by the film’s curiously ambiguous finale. It’s an energetic mess, diverting but ultimately derailed by its inability to stay focused.