Just before taking an irrevocable and tragic step, Caroline talks to Claire, her lycée friend. Later, Claire gathers five other school friends, and tells them Caroline's secret. The six agree to wage a guerrilla war against their philosophy teacher, the sarcastic and belittling M. Terrien, the cause of Caroline's despair. After seeking advice from Mayard, the school's guidance counselor and a leftist with a police record, the six look for evidence that could get Terrien fired. They strike gold, and then raise the stakes. Sarah, one of the six, hatches a deadly plan.