Guilt as Hidden Motive
Letting a character's guilt over a past wrong shape what they do now. The wrong may come out late or only be hinted at, but it colors every choice.
Gran Torino
Walt carries the memory of killing an enemy child soldier who was trying to surrender. It explains his gruffness and his choice at the end. He does not want Thao to live with the same stain.
Biutiful
Uxbal is haunted by the harm his choices cause. He feels responsible for the expulsion of the Senegalese and the deaths of the Chinese workers. Guilt shapes the way he spends his last weeks.

