Twins Pedro and Paulo are "two sides of the truth" and rivals from birth. As adults the principal source of their differences is politics - Pedro is a monarchist while Paulo wants a republic. Even in their choice of lovers they compete. Both are enamored of Flora, a modest, retiring girl whose temperament the narrator, Counselor Aires, calls "inexplicable." While Flora can't make up her mind between the two brothers, when she dies, the two brothers swear perpetual reconciliation on her tomb. But even then the two continue to dispute - as deputies in Brazil's congress. The book ends with the brothers once again swearing eternal friendship, this time on their mother's deathbed.