In the Days of the Comet by H.G. Wells

A world plagued by war, inequality, and disillusionment undergoes a miraculous transformation when a green comet changes Earth’s atmosphere. As the chemical shift alters human consciousness, conflict is replaced by reason, peace, and social harmony. The protagonist, once consumed by jealousy and rage, finds himself reborn in this new utopia. The story mixes science fiction with philosophical and political speculation. It’s a hopeful vision of sudden evolution through cosmic intervention.