The constant wrangling we see in The Romantics, directed and adapted from her own novel by Prozac Nation screenwriter Galt Neiderhoffer, might leave us emotionally drained if only we cared more, or perhaps knew more, about the characters at the heart of her talky melodrama.

This much we do know: A group of well-to-do Yalies have gathered along the picturesque Long Island shore for the marriage of ruggedly handsome Tom (Josh Duhamel) and his spoiled, emotionally distant bride-to-be Lila (Anna Paquin).

That they lack any real chemistry is apparent even to themselves – Tom seems to acknowledge as much, however tacitly – and further complicating their impending union is Laura, Tom’s still-smitten ex and Lila’s maid of honor. Played by Katie Holmes, at her most compelling since 2003’s Pieces of April, Laura is more jilted than jealous. She senses, rightly, that years of on-again, off-again dating, fly-by-night (but never casual) flings and ensuing separations have done little to cool Tom’s feelings for her.

There’s nothing novel about the premise that brings these pseudo-intellectuals together for a turbulent evening of drinks, nostalgia and nonstop bickering, but what Neiderhoffer does well is paint Laura and Lila with brushstrokes so intriguing that her lack of follow-through ultimately frustrates. We witness their most intimate exchanges – with Tom, and then with each other – performed with such bitter conviction by Holmes and Paquin that we want to know more.

Who is Laura, beneath her scholarly façade and her wounded outbursts, so eloquent they sometimes sound scripted? Why does she remain close with Lila, when the petty animosity that divides them seems so palpable? And what accounts for their mutual fascination with Tom, a mostly inarticulate slab of eye candy, apart from his precious habit of reciting Keats during foreplay?

Where Neiderhoffer underachieves is in fleshing out these characters as anything more than plot devices, endowing them with personalities engaging enough to make their squabbling poignant.

If Laura and Lila feel like rough sketches, promising but incomplete, their friends and family – for whom the director has assembled a formidable cast, including Malin Akerman, Adam Brody and Elijah Wood, wasted both literally and figuratively as Lila’s hard-partying brother – seem hastily penciled in, so slightly realized they threaten to disappear altogether. As David Byrne once observed, they talk a lot, but they’re not saying anything.

It’s a shame, because there’s a scene, right before the actual wedding – which, it must be said, ends fittingly – when Holmes and Paquin’s contentious banter really resonates. Watching them argue over a dress Lila bought back in New Haven, playing every card in their arsenal, we are privy to an outpouring of emotion so rancorous it’s hard not to be affected on some level. If only we had a better feel for these people, some reason to care as much as they clearly do, who is to say how satisfying The Romantics might have been?