A single event spawns all others in Alejandro González Iñárritu’s sophomore wonder, 21 Grams, yet it doesn’t occur anywhere near the beginning of the film.

A fateful car accident is at the heart of the film’s plot. Up until the moment when the collision unfolds onscreen, we’re allowed to see only snippets of it alongside a hodgepodge of scenes recalling less painful (if not happier) moments before the catastrophe, as well as glimpses into its disastrous consequences. Iñárritu’s decision to slice the film’s narrative into an intricate sequence of short, hard-hitting vignettes allows for an almost voyeuristic glimpse into the characters’ lives—like flipping through a photo album of scenes. The technique is similar to that employed in his eye-opening directorial debut, Amores Perros—merging form and content in a gritty web of ruptured lives told from an even further ruptured perspective. In 21 Grams, though, the technique is upped to Memento-like dimensions, with past, present and future jumbled up into a cinematic timeline with no strict patterns.

The car accident links the lives of three people through a chain of pain, remorse and isolation. There’s Christina Peck (Naomi Watts), whose way of coping with tragedy leads her into a self-destructive bout with drugs and depression. Paul Rivers (Sean Penn) is always seconds away from cardiac failure and he desperately clings to any hope for life even as he takes long, painful drags from countless cigarettes. Then there’s Jack Jordan (Benicio del Toro), an ex-con whose fanatical love for Jesus—an obsession which reformed his criminal ways—will be challenged by the car crash. The lives of all three characters will converge at both a physical and emotional level, yielding brutally frank glimpses at death and the toll it exacts from living.

The three leading actors’ performances are beyond praise. Del Toro’s quietly charged portrayal of Jack paints a compassionate man whose very love for Jesus blinds him into eschewing familial relations for one that exists in the abstract, while Penn can be charming, sad and pitiful all in the same shot. Most impressive, however, is Watts as a bereaved mother, unrelentingly peeling back layer upon layer of unmentionable grief. Many of Watts’s best moments would’ve neared over-the-top drama in the hands of many other actresses, yet the camera’s unforgiving close-ups of her convincingly pain-distorted features aid in conveying a woman tinged by death’s aftermath.

Death is precisely what this film is about—what death takes from us, what it leaves behind. The film’s title refers to the amount of body mass a person is said to lose at the exact moment of death—the weight of the soul, some might say. The film’s narrative tiptoe dance through the past, present and future challenges this saying by reminding us repeatedly of just how much the characters once had, and asking us to decide how much they’ve lost through the death of others. How much they’ve gained, on the other hand. The film’s beautiful cinematography at the hands of Rodrigo Prieto juxtaposes heart-wrenching scenes with visions of birds framed against a dusky sky—images of life and death, of beauty and its counterpart. The film’s ending leaves us pondering death’s contradictory tokens, while Penn’s voice echoes insistently: “How much do 21 grams weigh?” Iñárritu leaves it up to us to decide.

—Jackeline Montalvo