"Nemesis" is set during a polio epidemic in 1944 in the Weequahic neighborhood of Newark, New Jersey. The story revolves around Bucky Cantor, a 23-year-old playground director and teacher, who struggles with feelings of duty and fear as he witnesses the effects of the epidemic on his community and the children he supervises. The novel explores themes of fear, guilt, and the human response to epidemic crises, culminating in a personal and communal tragedy that impacts Cantor's life profoundly