Reuven is very good at math and his father wants him to become a mathematician. He thinks he may want to become a rabbi instead. Reuven's mother is dead and he adores and admires his father. Although Orthodox, Reuven is a participant in the larger culture. He likes baseball and movies. He listens to the news and follows the war reports closely.
Danny is brilliant; he has a photographic memory and a thirst for knowledge. Danny wears the traditional tzitzit (prayer fringes) and earlocks of his ultra-Orthodox community, but is fascinated by the secular texts in the library that are forbidden to him.
David Malter writes articles about the Talmud. He uses an approach to studying Talmud that emphasizes grammar and rationalism. David is an ardent believer in Zionism and works hard to help gain support for a Jewish homeland. He admires the Hasidim for keeping traditions alive for hundreds of years. He is often sick, and as the book progresses, his health deteriorates. His son, Reuven, is often anxious about his health.
Reb Saunders carries the burdens of his entire community, and they are painful. He commands absolute loyalty from everyone, including his family. Reb does not speak to Danny except when they study. He uses their study sessions to give him the guidance he believes he needs. Reb uses silence as a tool to teach Danny compassion.