Paul Braconnier is an elderly gardener trapped in a loveless and bitter marriage with his alcoholic wife, Blandine. Living in a small village, Paul endures constant nagging and manipulation from Blandine, leading him to feel increasingly desperate. The tension rises when Paul overhears his wife plotting to kill him for his life insurance money. Frustrated and feeling cornered, Paul visits famed criminal lawyer, Maître Aubanel, who has successfully defended many murderers. During their meeting, they engage in a hypothetical discussion on how one might justify killing their oppressive spouse.

Upon returning home, Paul finds himself contemplating the unthinkable and executes a meticulous plan to rid himself of Blandine. The community, aware of their rocky relationship, finds Paul's newfound freedom suspicious. As authorities investigate, Paul's interactions with those around him become peppered with dark humor and irony. The hypothetical discussions turn chillingly relevant, leaving the villagers and officials questioning where the line between victim and villain truly lies. Without revealing too much, the unfolding events force Paul and those around him to confront uncomfortable truths about morality and justice.