In “Brothers” we have a movie that’s sometimes too intense for its own good, that ends without really resolving its issues, and that relies too much on a plot point that isn’t given the weight it needs. And yet I like it. Based on an acclaimed Danish film from 2004, it has strength and maturity beyond that of many adult dramas. I jotted in my notes early on that it takes highly skilled actors to make a story this melodramatic work, and “Brothers” has them: Natalie Portman, Jake Gyllenhaal, Sam Shepard, and — to a much lesser extent — Tobey Maguire. If Maguire and Gyllenhaal had switched roles, we might have really had something.

They play brothers, which in itself was a smart move, given their physical resemblance. Maguire is Capt. Sam Cahill, a Marine heading out for another tour in Afghanistan in late 2007. He is the pride and joy of his retired Marine father, Hank (Shepard), and a local hero at the fictional California military base where they live. Sam’s wife, Grace (Portman), and their two young daughters, though they miss him, are resilient in his absence. They’ve been through this before.

Gyllenhaal is Tommy Cahill, a total screw-up. He’s released from prison for armed robbery just days before Sam’s deployment, and immediately butts heads with their disappointed father. Grace doesn’t care much for her brother-in-law. The kids hardly know him. But there he is, part of the family, and he’s not going anywhere.

Grace receives word that Sam has been killed in Afghanistan. This is less than a half hour into the film, and we know it can’t be true: Maguire is the top-billed star. Sure enough, he and another soldier, Pvt. Willis (Patrick Flueger), are being held prisoner by cruel insurgents. It’s crucial to the story, however, that Grace, Tommy, and everyone else back home think Sam is dead. Tommy, leaning toward redemption after his prison stint anyway, sees a chance to step up and be useful, comforting Grace and being an uncle to the girls.

The film’s first hour delivers most of its best moments. Director Jim Sheridan (“My Left Foot,” “In America”), working from a screenplay by David Benioff (“25th Hour,” “The Kite Runner”), has Portman and Gyllenhaal — two of the best actors of their age group — doing fantastic work as Grace and Tommy. Both characters are grieving but do not wallow in self-pity, and they find solace in their burgeoning friendship. This is played believably, not at all like the soap opera it could have turned into given the subject matter.

Maguire, unfortunately, seems out of his depth, particularly in the inevitable aftermath of Sam’s return from Afghanistan to civilian life. Sam is ruined, haunted by the things he had to do while imprisoned, and finds it difficult to come back essentially from the dead. There is much potential there, but Maguire’s performance often goes over the top. Moreover, there’s a particularly traumatizing thing that happens during Sam’s captivity that the film doesn’t take the steps necessary to explore in depth. Instead, it hangs there awkwardly, apparently crucial to Sam’s mental health but not granted the screen time and thoughtful consideration it needs.

And yet, as I said, I like the movie, flaws and all. Its flaws are interesting too. Why did Benioff and Sheridan give that plot point the short shrift? Or are the raw materials there, and Maguire simply failed to convey them? Would the movie have been better if it only explored the Grace-and-Tommy dynamic — if Sam had really died? Those are your discussion questions. “Brothers” is actually worth discussing, which is something else that makes it different from most adult dramas.

B (1 hr., 50 min.; R, a lot of harsh profanity, brief strong violence.)