There is no way to describe the instant of death, as it doesn’t leave you the time to document it. Nevertheless, the aftermath of death weighs heavily on those left behind. With little knowledge of what this aftermath will entail, one thing is eerily certain. The instant your pulse ceases, you will lose a fraction of your literal weight to be figuratively dispersed to others – precisely 21 grams. In reality, the amount lost is minuscule; metaphorically, it can be the heaviest weight one could possibly bear. While no documentation exists to describe this instant of death, one does for describing its weighty implications.

Alejandro Gonzalez Inarritu’s “21 Grams” (Focus Features) is a film about those implications and the lives they affect. Inarritu, whose directing efforts in “Amores Perros” won him international acclaim, has tackled his latest production with screenwriting sidekick Guilermo Arriaga, also of “Perros” fame. Add to the mix actors Sean Penn, Benicio Del Toro and Naomi Watts, and what could have been a somber film gains the delicate yet driving vehicle by which a pertinent masterpiece is achieved.

“21 Grams” follows the non-linear and eventually intertwining events that befall an ex-con struggling with religion (Del Toro), a dying math professor (Penn) and a young, grieving widow (Watts). The film depicts the anticipation, approach and aftermath of death while bringing to light the hope that can follow it. After viewing the film, it is hard to imagine a better cast to effectively portray such a plot; each actor presents his complex character with immense finesse.

Del Toro’s performance as Jack Jordan displays a man driven away from alcoholism and crime via the avenues of religion. But after religion denies him the answers to an awful accident in which he is involved, Jordan’s world begins to cave in. Alone even in the faith that promised him salvation, he approaches the crossroads of either continuing relentlessly forward or regressing into depravity.

“I don’t think my character used religion as a drug as he used alcohol in the past,” said Del Toro in a recent Hatchet interview with the cast and crew of “21 Grams.” “Religion was a crutch and reason to get his life together …He’d come to expect so much out of religion that when it didn’t live up to what he’d expected, he started to doubt everything about it.”

Del Toro undeniably lives up to Inarritu’s claims that he is a “cinematic animal,” as every facial expression grasps his character’s torment, desperation and eventual hope.

Penn’s portrayal of mathematician Paul Rivers demonstrates a remarkable ebb and flow with death as he awaits a heart transplant. In choosing the role, Penn claimed he was simply drawn to his character’s traits and Inarritu’s directing.

“As was the case with this movie and others I’ve been involved in, this was just something I needed to do in my life,” he said. “Life is my art, and my art imitates that life.”

Watts’ portrayal of the recently widowed Cristina Peck is enchanting. Left with nothing but material shadows of what she once had and the memories of her own drug-addicted past, Peck also must choose to collapse or hold out hope for the future.

“The only way I felt to portray this kind of character was to spend time with people who had been through something like this,” Watts said of her preparation for her role. “I think I came close with my portrayal, but that real pain of losing someone is something you can’t truly represent without having it happen to you.”

But despite the awful suffering depicted in the film, “21 Grams” is not weighed down by sorrow, a fact that must be attributed to the collective work of the cast and crew.

“The film focuses on finding hope in the darkest of circumstances” said Arriaga. “What happens to these people are horrible things, but in all the darkness there is still hope and a reason to keep on living. No matter how much pain and misery they go through, this is still a story about love.”

Along with the direction, writing and acting, has “21 Grams” is unified by its rapid editing through time. The film has a spectacular ability to keep its viewer guessing about its character’s complex personas. One minute a character appears arrogant, minutes later he appear humble. One moment good, the next he is evil.

In dissolving the simplicity of the difference between good and evil, what “21 Grams” aims at is beyond passive reception. Quite the contrary – it cannot help but maintain a constant force of introspective interaction. Judgment based on good and evil becomes absurd; just as the characters do, we deal with our circumstances in ways that are alternately horrible and beautiful. We are generous and greedy, sadistic and philanthropic, at different points in our lives.

Inarritu made his point succinctly: “I didn’t want the film to dictate who was good or who was bad. That’s too simple.” In working together, such a view was not only Inarritu’s but Arriagas as well, one conceived even before the first word was written.

“I believe characters shouldn’t only surprise the viewer, but the writer, too,” said Arriaga. “I’ve always been against researching my characters, giving them rules or putting them across as simply good or bad. That’s just not the human condition in life.”

As such an execution demands, the viewer inevitably sees how easily he is swayed, given what he is shown in the present. Thinking beyond the immediate moment is a difficult task, but a task that’s proven necessary if any true notion of humanity is to be arrived at.

Altogether, “21 Grams” is an incredibly human tale about tragedy and the catharsis that follows. Death is a part of life but, as “21 Grams” masterfully shows, it is a part of life that can lead to rebirth if people can open their eyes to the life that still exists all around them. n