21 Grams is a 2003 American psychological drama film directed by Alejandro González Iñárritu from a screenplay by Guillermo Arriaga, based on a story by Arriaga and Iñárritu. The film stars Sean Penn, Naomi Watts, Charlotte Gainsbourg, Danny Huston and Benicio Del Toro. The second part of Arriaga's and Iñárritu's "Trilogy of Death", preceded by Amores perros (2000) and followed by Babel (2006), 21 Grams interweaves several plot lines in a nonlinear arrangement.
The story is told in a nonlinear manner. The following is a chronological summary of the plot: