There’s a scene in this new film by Mexican filmmaker Alejandro Gonzalez Inarritu (his first in English) in which a young woman, distraught over the deaths of her husband and two young daughters, stares at the ties still hanging in her bedroom closet, and just for a moment the sight of them, and the expression on the widow’s face, capture the feeling of grief at unmentionable loss that “21 Grams” is all about. Unfortunately, the impact isn’t sustained elsewhere in the picture, which is technically flamboyant in a fashion that catches the eye but actually lessens its ability to touch the heart. Atom Egoyan’s masterpiece “The Sweet Hereafter” dealt with the same subject in a far subtler, more direct and piercing way, and by comparison the new picture, while sporadically effective in a splashy, rather brutal fashion, is overall a disappointment.

The film centers on three people whose lives intersect. One is Paul (Sean Penn), an academic suffering from a heart disease requiring a transplant. The second is Jack (Bemicio Del Toro), an ex-con who’s found Jesus. And the last is Cristina (Naomi Watts), a wife whose happiness is shattered by the accident that kills her whole family. But also deeply involved are their spouses: Paul’s wife Mary (Charlotte Gainsbourg), who’s anxious to have a child by her husband; Jack’s wife Maryanne (Melissa Leo), who wants to hold her family together no matter what her husband might have done; and Cristina’s husband Michael (Danny Huston), whose death eventually draws Paul to her.

The ways in which these characters become related aren’t terribly surprising, but it would still be unfair to detail them too explicitly, because the picture is constructed like a puzzle, with the pieces shuffled out of chronological and logical order, so that the overarching tale of loss, obligation and revenge has to be built up from the shards by the viewer as he watches. The effect isn’t unlike that which got Inarritu so much attention in his previous film, “Amores Perros,” which also linked apparently unconnected plot threads, gradually revealing how they were connected. The gritty, hyperkinetic visual style that the director and cinematographer Rodrigo Prieto employ here resembles that of the earlier film, too.

But in this instance the filmmakers are dealing with more substantial human themes–love, loss, guilt, redemption, gratitude–than before, and the style, which was fairly well suited to the shallow theatrics of “Amores Perros,” rather cheapens the material here. (Once again, a comparison with Egoyan’s beautifully restrained, solemn film highlights the deficiencies.) And it has to be admitted that the structural convolutions aren’t very successful in obscuring where the story is headed. By the time you’re forty minutes in, it’s pretty easy to predict how it’s all going to turn out. The non-chronological approach isn’t terribly beneficial to the performances, either, making it difficult to appreciate how well the actors are conveying their characters’ transformations, which necessarily come across as abrupt. Watts suffers most from the effect, but Penn does as well; actually both are quite impressive, but would probably be more so if the story were played straight through and their contributions weren’t constantly being interrupted by shifts which lurch into later or earlier events. Del Toro fares better; but that may simply be because, as written, Jack is a more complicated, penetrating figure than the others. He’s also paired with the most remarkable spouse: Leo’s portrait of a plain woman devoted to preserving the little she has, regardless of the cost, is powerfully affecting. By contrast Gainsbourg is clipped, and Huston has too little screen time to register anything but a generalized likeableness.

As “21 Grams” roars to its fatalistic finale, it grows increasingly shallow and less absorbing; whatever substance the film possesses at first is gradually dissipated by the emphasis on style for style’s sake. If the title indicates, as Penn tells us toward the close, the weight of the human soul, then it might be argued that this flashy but curiously unaffecting picture ultimately comes up short by that amount, for it’s soul that it really lacks.