The story follows a narrator who meets a family with four intellectually disabled adult children, known as the idiots, while traveling near Ploumar in Brittany, France. The story explores how the parents married and had their four children, struggling with the criticism of their neighbors who saw the children as useless. This leads to increasing sorrow, misfortune and desperation for the family. Ultimately, the mother Susan kills the father Jean Pierre in a fit of anger, before herself dying on the beach. The theme examines society's intolerance of things outside its control, like mental retardation.