21 Grams is one of the best films of 2003, boasting daring direction, gripping performances and a well crafted storyline. The title is not a drug reference, but is instead an allusion to the weight a person loses at the precise moment of death.

Sean Penn and Naomi Watts deliver the best roles of their careers, while Benicio Del Toro builds on the promise of his Academy Award winning role in Traffic. Watts lights up the screen with her portrayal of a modern-day Florence Henderson who transforms into a drug addict after death strikes close to home.

Mexican director Alejandro González Iñárritu convincingly captures these three individuals coming together through tragedy, while mastering non-linear storytelling. This style of fragmented plot structure turns 21 Grams into a cinematic puzzle that doesn’t become clear until all the pieces are in place.

Penn plays Paul, a math professor who refers to himself as a member of the “pre-corpses club,” waiting for his failing heart to give out. He drags an oxygen tank when he walks and waits for his wife to leave long enough to sneak himself a smoke.

After giving up hope on his own heart, a fatal car accident claims the lives of a father and his two daughters and Paul finds himself with a new beater in his chest and the thought of connecting to the person who has given it to him. What Paul finds, though, is an empty house that echoes with the loneliness of a heartbroken widow, Christine (Watts).

Christine is a blonde beauty whose dream has become a nightmare, leaving her with haunting memories of her lost family. She numbs the pain with a line of coke and some whiskey. That is, until Paul appears.

Together they hunt down the man responsible for the deaths — a criminal who has found Christ — played by the haunting Del Toro. Crippled by his guilt and confused as to why God allowed such a tragedy to occur, Jack (Del Toro) is among modern cinema’s most compelling characters. What begins as an act of gratitude on Paul’s part slowly becomes an act of murderous chivalry.

Iñárritu tells the story in abstract fashion, giving the audience bits and pieces of the story. Despite this, the director manages to flawlessly build on the suspense, leaving viewers in the dark as to what may occur at any given moment.

This approach could’ve been distracting in other hands, but Iñárritu keeps 21 Grams consistently brilliant and draws audiences even further into each character’s misguided choices.

Penn doesn’t stray from the grief stricken character he played in Clint Eastwood’s Mystic River. Now, Penn has two award-caliber performances, and is a shoe-in for a Best Actor nomination.

Watts is fantastic as the vengeful Christine, giving her all and making even the most mundane scenes dramatic and memorable. She has clearly grown as an actress, and gives arguably the best female performance of last year.

21 Grams’ most fully developed character, Jack — Del Toro’s most convincing work to date — is one of the most eerie aspects of the movie. Del Toro steals scenes from veteran Penn and, with his ability to create a fully rounded character, gives Jack a unique persona not often seen in modern film.

The film’s only low point is a sluggish and flavorless start, with a few interesting character moments but nothing remarkable. That soon fades as the film sinks its teeth into audiences and doesn’t relent for the remainder of the movie.

Since the release of Memento, many directors have been using alternate chronology as an effective tool in story telling, but no film has used the technique as well as 21 Grams. The movie’s fresh feeling is impressive given that this road has been traveled often in the last few years.

The film is an angst-filled theatrical rollercoaster of emotions, which has been a theme for some of this winter’s best, from Mystic River to House Of Sand And Fog — films anything but perfect and sweet.

21 Grams isn’t cluttered with an abundance of special effects or overshadowed by an epic love story. Instead, the film is grounded by amazing performances and the dark themes of revenge, grief and violence.