Naomi Watts said her role in *21 Grams* was emotionally gruelling: she played Cristina Peck, a mother who turns to drugs and alcohol after her husband and children are killed in a hit-and-run. The performance mattered to Watts’ later career too, as María Belón, whom she portrayed in *The Impossible*, reportedly became a fan of her work after seeing the film.

To prepare, Watts met people in grief support groups and at a rehabilitation centre, listening to their experiences. She said she cried on set every day for about a month and relied on her instincts, while sometimes needing the director’s help to reconnect with a scene; she also said her own experience of loss informed the role.