Taking its name from the belief that the body becomes twenty-one grams lighter   upon death, the English-language debut from the director of Amores            Perros is a strong, emotional ride with impressive performances from Sean     Penn, Benicio Del Toro and Naomi Watts and a unique non-linear structure. The  compelling story of three lives intertwined and torn apart by tragedy unfolds  when a violent car crash brings together a college prof (Penn), an ex-con (Del Toro) and a young mother with a shattered past (Watts), allowing complicated     and conflicted emotions and pasts to come to light amidst the turmoil.         "...defies filmmaking convention and leaves an indelible mark on the           collective psyche" (Bill Muller, Arizona Republic).                      Alejandro Gonzalez Inarritu---USA---2003---125 mins.