Before seeing “Brothers,” I had a brief conversation about it with my brother. “Is it a horror movie?” He’d asked. Feeling suddenly defensive, I pressed for clarification. “In the trailer, she says, ‘I thought you were dead.’ Is he a ghost?”

Ah, interesting. Maybe he is. This is Tobey Maguire we’re talking about, seeming cadaverously thin, and capping the movie off by asking the audience, “Can I live again?” He plays an upright Marine gone missing and presumed dead in Afghanistan, leaving his wife to be looked after by his delinquent kid brother. The wife is played by Natalie Portman, and the brother is played by Jake Gyllenhaal, so that’s some dangerously easy looking, both before and after.

Except that when Tobey comes home, incongruously alive, it gets a lot harder. And not just because Portman, come to think of it, appears here rather alarmingly reedy herself. There is horror in this movie, to be sure — particularly in the brutal and transformative Taliban captivity Maguire’s character endures while MIA. But with that in mind, and the fact that “Brothers” actually is a remake of a 2004 Danish drama, with Sam Shepard in its cast, we’re not wrong to hope for something more poetic and philosophical than a haunted Hollywood soap opera. At the very least, it should allow us to retain our self-respect while studying the visual affinities between a pair of similarly dreamy-eyed young stars, just as “The Departed” — another Americanized foreign hit — did with Matt Damon and Leonardo DiCaprio.

The director of “Brothers” is Jim Sheridan, whose other credits include “In the Name of the Father” and “Some Mother’s Son,” so at least the family dynamics do come naturally. Also, when not cross-cutting between Middle-Eastern persecution and Midwestern recreation, Sheridan sets his snowy, funereal mood with exacting patience. “Brothers” values poise and understatement, and that’s fine. But there’s also a nagging sense that the movie itself, like the married couple at its core, suffers from insufficient meat on its bones.

I mentioned Shepard not just because he’s written great plays involving manly, ghostly, family drama, but because his presence is what’s best about “Brothers.” Yes, Gyllenhaal has some nice moments of drunken desperation and amends-making; and Maguire acts his heart out, or at least bugs his eyes out, during imperative breakdown scenes; and Portman sharpens the blade of her beauty into recognizable signifiers of maternal inclination and grief; but Shepard’s portrayal of the young men’s father, a favorite-playing combat-veteran Marine himself, is the movie’s anchor. He’s the faded patriarch, at once burrowed into old grudges and woundedly aloof, and this marvelously coiled-up performance precludes all the potential cliches. Mare Winningham, underused, plays the brothers’ mother, but it’s in Shepard’s face and testy manner that the full family backstory is revealed.

If only it’d been him writing the script instead of David Benoiff, whose screenwriting career, since beginning auspiciously with an adaptation of his own novel “25th Hour,” has declined into the likes of “Troy,” “The Kite Runner” and “X-Men Origins: Wolverine.”

“We’re brothers, and brothers look out for each other,” Liev Schreiber said to Hugh Jackman in “Wolverine.” “You’re my brother,” Gyllenhaal and Maguire say to each other in “Brothers.” The idea being that fraternal obligation is sort of automatically, grandly dramatic. In which case, please allow me to conclude here so that I may get word to my brother right away: No, it’s not what you think!