21 Grams is a 2003 American tragedy drama film directed by Alejandro González Iñárritu and written by Guillermo Arriaga. It stars Sean Penn, Naomi Watts, Danny Huston, and Benicio del Toro. Like Arriaga's and González Iñárritu's previous film, Amores perros (2000), 21 Grams interweaves several plot lines, around the consequences of a tragic automobile accident. Penn plays a critically ill academic mathematician, Watts plays a grief-stricken mother, and del Toro plays a born-again Christian ex-convict whose faith is sorely tested in the aftermath of the accident. 21 Grams is presented in a non-linear arrangement where the lives of the characters are depicted before and after the accident. The three main characters each have 'past', 'present', and 'future' story threads, which are shown as non-linear fragments that punctuate elements of the overall story, all imminently coming toward each other and coalescing as the story progresses.
Jack Jordan (Benicio del Toro) is a former convict who is using his new-found religious faith to recover from drug addiction and alcoholism. Paul Rivers (Sean Penn) is a mathematics professor with a fatal heart condition. Unless he receives a new heart from an organ donor, he will have less than one month to live. Paul's wife wants him to donate his sperm so she can have his baby, even if he dies. The two are civil to one another, yet distant. Cristina Peck (Naomi Watts) is also a recovering drug addict, and now lives a normal suburban life with a supportive husband and two children. She is a loving mother and active swimmer, who has left her days of drugs and booze behind. These three separate stories/characters become tied together one evening when Jack kills Cristina's husband and children in a hit-and-run accident. Her husband's heart is donated to Paul, who begins his recovery. Cristina is devastated by the loss and returns to drugs (flunitrazepam and ketamine) and alcohol. Paul is eager to begin normal life again, but he hesitantly agrees to his wife's idea of surgery and artificial insemination as a last-ditch effort to get pregnant. During consultations with a doctor before the surgery, Paul learns that his wife had undergone an abortion after they had separated in the past. Angered, Paul ends the relationship. He becomes very inquisitive about whose heart he has. He learns from a private detective that the heart belonged to Cristina's husband, and begins to follow the widowed Cristina around town. Jack is stricken with guilt following the accident. Despite his wife's protests to keep quiet and conceal his guilt, Jack tells her that his "duty is to God" and turns himself in. While incarcerated, he claims that God had betrayed him, loses his will to live and tries unsuccessfully to commit suicide. He is released after Cristina declines to press charges, as she realizes that putting Jack in prison will not bring her family back. When Jack is released, he is unable to reincorporate himself into normal family life, and instead leaves home to live as a transient. He works a manual labor job and defaces his Christian tattoos with a knife. Paul finds an opportunity to meet Cristina and eventually reveals how the two of them are connected. Desperately needing one another, they begin to develop a relationship. Though Paul has a new heart, his body is rejecting the surgery, and his outlook is grim. As Cristina begins to dwell more on her changed life and the death of her girls, she continually focuses on a desire to exact revenge on Jack. She goads Paul into agreeing to murder him. Paul meets with the private detective who originally found Cristina for him. Paul also purchases a gun from him and learns that Jack is living in a motel. Paul and Cristina check into the motel where Jack is also staying. When Jack is walking alone, Paul grabs him and leads him out into a clearing at gunpoint with the intention of killing him. Paul is unable to kill Jack, who himself is confused, shaking and pleading during the event. Paul tells Jack to "just disappear" then returns to the motel, lying to Cristina about Jack's death. Later that night, while they are sleeping, Paul and Cristina are awakened by a noise outside their door. It's Jack, who, still consumed by guilt and inner torment, orders Paul to kill him and end his misery. There is a struggle, and Cristina blind-sides Jack and begins to beat him with a wooden lamp. Paul has a heart attack and shoots himself to avoid dying from asphyxia. Jack and Cristina rush Paul to the hospital. Jack tells the police that he has shot Paul, but he is released. The conflict between Cristina and Jack remains unresolved (they meet in the waiting room after Paul's death. If they converse, it is not shown.). Cristina learns in the hospital that she is pregnant. After Paul's death, Cristina is seen tentatively preparing for the new child in one of her daughters' bedroom which she was previously emotionally unable to enter since her daughters' death and Jack is shown returning to his family.