Though Adah is Leah's identical twin sister, at least as a child she was very much night to Leah's day. Where her sister was a tireless tomboy, Adah was crippled, the whole left side of her body paralyzed from birth. Where Leah was idealistic, Adah was a cynic preferring to view things backward rather than forward; and where Leah threw herself into life, Adah held back, preferring to pretend she was merely a wry observer rather than a participant. She even refused to speak except in emergencies. As Adah ages, however, she loses these characteristics to a certain extent. While struggling to save herself from death one night in the Congo, she realizes that she cares about her life, and so is not a detached observer. A neurologist friend helps her overcome her handicap. Her cynicism diminishes somewhat as she matures. Adah even finds a religion that she can truly believe in, the religion of science. She becomes a brilliant researcher, studying the life of viruses. Yet Adah cannot completely overcome the backward-reading girl she once was. She loves and admires the viruses she studies, and dismisses the idea of human cosmic importance as a pleasant myth. In addition, she looks back longingly on her handicap and her tendency to see the world from a wholly different angle, revealing that a significant portion of that person remains in her.
