Paul (Sean Penn) has less than a month to live, he's on the waiting list for a heart transplant, and his wife (Charlotte Gainsbourg) is determined to get pregnant with his child before it's too late. Meanwhile, Cristina (Naomi Watts) is a happy mother with a loving husband and two daughters but she loses her family in an instant to an unpredictable accident. Finally, Jack (Benicio Del Toro) is an ex-con and born-again Christian struggling to support his wife and two children while battling his own guilty conscience. When these three parties come together, explosively, they make each other behave in impulsive, violent, and destructive ways. 21 Grams takes the viewer on a jolting journey through sickness, suffering, morality, revenge, and last but not least, the sometimes welcome peace of death.