The awesome aspiration of 21 Grams is to understand the human soul; the title referring to the weight supposedly lost at the moment of death - a spiritual measure. Showcasing some of the year's finest screen acting - from Sean Penn, Naomi Watts and Benicio Del Toro - Mexican director Alejandro González Iñárritu has created an astonishing account of faith and redemption. As with Iñárritu's first film, the acclaimed Amores Perros, an auto accident links three disparate lives: Watts's husband and two daughters have been run over and killed by Benicio Del Toro's drunk-turned-Jesus freak; Penn's maths professor receives the husband's heart and is eventually drawn into an affair with his widow. Their fates are bound as the extended aftermath of the central tragedy unravels. Iñárritu again uses a non-linear, mosaic narrative technique to lure us into a maze of contradictions that eventually lead to revelation - it is an extraordinary vision.

Paul Rivers, an ailing mathematician lovelessly married to an English émigré; Christina Peck, an upper-middle-class suburban housewife and mother of two girls; and Jack Jordan, a born-again ex-con, are brought together by a terrible accident that changes their lives.