The narrative unfolds in a non-linear structure, yet here’s a chronological overview of the gripping story:
Jack Jordan (Benicio Del Toro), a reformed ex-convict, strives to rebuild his life by embracing a newfound religious faith that helps him combat his struggles with drug addiction and alcoholism. Simultaneously, Paul Rivers (Sean Penn), a mathematics professor, faces a life-threatening reality with a fatal heart condition that leaves him with mere weeks to live unless he finds a suitable organ donor. The tension in his marriage is palpable as his wife pressures him to consider sperm donation, determined to have a child even after his passing, resulting in a civil yet distant connection between them.
In contrast, we meet Cristina Peck (Naomi Watts), a dedicated mother and recovering addict, now enjoying a tranquil suburban lifestyle with her loving husband and their two children. Her new life, filled with joy and the pursuit of swimming, starkly contrasts with her past filled with chaos and addiction. However, the fates of these three characters intertwine one fateful evening when Jack, tragically and recklessly, takes the lives of Cristina's husband and children in a hit-and-run incident.
The repercussions of this horrifying event spiral out of control: Cristina is left heartbroken and strives to numb her pain through drugs and alcohol once again. On the other hand, Paul, now with a new heart, clings to the hope of life beyond his surgery, but feels conflicted about his wife’s wishes for artificial insemination. A shocking revelation about an abortion during their separation drives a wedge between them, leading Paul to sever ties.
Haunted by guilt, Jack grapples with the aftermath of his actions. Despite urging from his wife to remain silent, he ultimately confesses, believing that his "duty is to God." His prison life is punctuated by despair, but upon his release—after Cristina decides against pressing charges—he finds it impossible to reintegrate into society and instead becomes a wandering laborer.
Paul, meanwhile, tracks down Cristina, revealing their intertwined lives, and the desperate duo begins to form a connection. As Paul faces complications from his surgery, Cristina wrestles with her grief and a burgeoning desire for vengeance against Jack, eventually persuading Paul to assist her in orchestrating Jack's murder.
The tension mounts as Paul arranges a confrontational meeting with Jack at a motel where he has been staying. In a pivotal moment, with Paul holding a gun, he confronts Jack but falters, instructing him simply to "just disappear" instead of pulling the trigger. This moment of hesitation leads to disastrous consequences when Jack unexpectedly appears at Paul and Cristina's motel later that night, urging Paul to end his life out of remorse. A violent struggle ensues, culminating in Paul suffering a heart attack and accidentally shooting himself in a frantic attempt to escape asphyxiation.
In a desperate bid for help, Jack and Cristina rush Paul to the hospital, and in an act of self-sacrifice, Jack claims responsibility for the shot but is released due to lack of evidence. The unresolved tension between Cristina and Jack hangs heavy in the air, and after Paul’s death, Cristina discovers she is pregnant. The story closes with her tentatively embracing the prospect of motherhood again, preparing a room once filled with her daughters’ memories, while Jack attempts to reintegrate and find peace within his own haunted past.
