21 Grams

Or Amores Perros without the dogs. This, at least, is the initial impression one gets of the new film from Alejandro González Iñárritu, again collaboring with screenwriter Guillermo Arriaga.

Again, there are three distinct storylines, though they are intertwined to a far greater extent than in the Mexican film and, indeed, ultimately combine together, as foreshadowed by a number of disorientating flashforwards. And again a car accident provides the axis around which all the human drama revolves.

Sean Penn plays Paul Rivers, a college professor in need a heart transplant. His estranged wife Mary (Charlotte Gainsbourg – clipped English tones and mannerisms slightly out of place) has returned to help in his hour of need, but also has an agenda of her own. She wants Paul's child; whether he is alive to see it born or grow up is secondary.

Benicio Del Toro plays Jack Jordan, an ex-con who has found religion. He won a pickup truck in a sweepstakes and, believing it to be a message from the Lord, has adorned the vehicle with the legend "Jesus Saves"

Naomi Watts plays Cristina Peck, an ex-junkie who has extricated herself from her former life and now leads a conventional middle-class existence with her architect husband Michael and two young daughters.

One evening whilst driving home Jack's concentration lapses and he wipes out Cristina's family in a hit-and-run. While Jack anguishes over what he should do, Cristina is asked whether her brain-dead husband's organs can be used for transplantation, thereby giving Paul a replacement heart.

Recovering in hospital after the operation, Paul wonders where his heart came from, the hospital's strict policy against disclosing the donor's identity giving the lie to an earlier moment – one of the film's few obvious lapses of judgement – where the donor's and recipient's families unwittingly pass one another in the hospital.

Undaunted, he hires a private investigator, who soon discovers the whereabouts of Cristina and Jack, who has since decided, contra his wife, that What Jesus Would Do is give himself up but is also experiencing increasing doubts as to the value of a Lord whose divine plan has cast him in the role of child-killer…

Paul establishes a tentative relationship with Cristina, who has responded to the trauma of losing her loved ones by going back to the drink and drugs, his motivation murky. Initially hesistant, she slowly responds, two desperately needy individuals clinging to whatever they think the other can offer them…

Finally, Paul decides they must confront Jack…

Even if 21 Grams lacks the sense of really seeing something new that made its predecessor so welcome, it is still a remarkably accomplished and, above all, mature piece of film-making.

Thus, while the hand-held camera is used to convey immediacy, it is never allowed to dominate over the content of the piece in the manner. (Elephant and the Dogme school, are you listening?)

Likewise, while there are necessarily allusions to other films – you cannot have a woman lose her family in an accident and go swimming without now recalling Juliette Binoche in Kieslowski's Blue, while the slow-burn accident-revenge element brings to mind Penn's own The Crossing Guard and Claude Chabrol's The Beast Must Die – there's never any sense that it's all a game of intertextual reference spotting without any connection to lived reality. (Yes, Tarantino, this one's for you.)

The three central performances are near perfect. Penn and Del Toro constantly put you on a see-saw as to which is better, each scenes seeming to surpass the one before it, while Watts adds to her growing dramatic list of impressive dramatic credentials.

In the end, though, it is Del Toro who emerges as first among equals. Whereas Penn's body – as distinct from his facial expressions and world-weary delivery – just looks just that bit too buff for a guy with a terminal condition, you really believe that Del Toro is going through hell with his character, the scene where Jack drunkenly attacks his religious tattoos with a heated knife a harrowing standout.

An equal, not a sequel, then, from one of the cinema's brightest hopes. Shame they couldn't have come up with a better title though…