21 Grams review

21 Grams has big themes and, boy, does it use them. Named after the weight the body loses at death (the soul departing, perhaps?), it asks how you quantify life in the context of what lives departed leave in their wake. Grief, guilt, fractured faith, vengefulness and sacrifice are the leftovers its characters, - who each walk a tortuous life-and-death tightrope, have to wrestle with. It's hefty stuff, for sure. But does the film punch its weight?

Well, almost. As a US debut for Alejandro González Iñárritu, who mauled us magnificently with his Mexican mutt movie Amores Perros, it's certainly compromise-free. His move to America goes like this: love's a bitch, then you die. He and his screenwriter Guillermo Arriaga don't talk down, and their stamp is clear as the film's choppy plotting coils around three stories. These intersect via a fateful, violent traffic accident that turns out to be pregnant with repercussion.

Quite a plateful, then. But it feels overcooked, as if Iñárritu is trying too hard to leave visible tooth marks. This is especially true in the plotting: the time structure jumps back and forth, and it's questionable just how much the film gains from the stunt. By the time it hits the 100-minute point, its engine is spluttering and repeating, with the plotting almost dictating the content, rather than the other way around.

Penn's speech on numerical theories feels shoehorned in, while his twinkly-eyed wooing of Watts is more plot-driven than character-rooted. Such moments lack the crunch of hard truth, even as the film's weathered visuals suggest a desperation to convince the audience this is the real deal.

Sure, your brain-motor will hum, and the themes of guilt and revenge do resonate with questions of justice, capital punishment and, arguably, post-9/11 America. In acting terms, too, there's plenty to chew on. Watts and Del Toro (both Oscar-nominated for their roles) positively roar with restraint, while the lesser-known Melissa Leo matches Benicio every step of the way as his long-suffering wife.

Only Penn is questionable: he makes a hard-to-swallow academic (and there's little justification in the script for him being one) and he gave an all-too-similarly tortured turn in Mystic River. Good as he is, you can hear the cogs whirring.

The same goes for the film. Yes, Iñárritu and Arriaga's virtuoso riffing will snag them another Hollywood gig as surely as it sparks debate. But 21 Grams may have hit harder as a no-tricks 90-minuter, cut lean and sleek. Sometimes, surely, it's what gets left behind that gives anything - be it people or films - its definition.