Naomi Watts (as a woman whose whole family is killed in one accident) and Benicio Del Toro (as a Jesus-loving ex-con) are good...but Sean Penn is just riveting. He's this addicted smoker who can't quit even while waiting for a replacement for his diseased heart...of course, he's more than that, but that's the image that stuck with me, personally.
These three peoples' stories, individually and intertwined, are told in choppy segments, seemingly thrown together at random. Is as though the director (Alejandro González Iñárritu) took a book, cut apart all the chapters, tossed them into the air and put them back together in the order they fell. But somehow, it makes sense. It may even make more sense that way.
It's pure emotion, this movie: Happiness, grief, terror, anger, lonliness, despair, guilt...there's no punches pulled and the camera is an unflinching witness to it all.