A sudden epidemic of white blindness spreads through an unnamed city, affecting everyone it touches. To contain the outbreak, the infected are placed in quarantine inside an abandoned asylum. There, without rules or leadership, society quickly collapses into chaos, violence, and desperation.
Among the group, one woman mysteriously retains her sight and secretly becomes their guide, helping them survive the brutal conditions. Outside the quarantine, society is also breaking down as the blindness spreads.
Eventually, the epidemic ends as suddenly as it began, and sight returns. The novel closes with a reflection on human fragility and moral blindness, showing how easily civilization can collapse when order disappears.