Software prodigy Josie Ashkenazi has invented an application that records everything its users do. When she visits the Library of Alexandria as a tech consultant, she is abducted in Egypt's postrevolutionary chaos with only a copy of the philosopher Maimonides' famous work to anchor her-leaving her jealous sister Judith free to take over her life. A century earlier, Cambridge professor Solomon Schechter arrives in Egypt, hunting for a medieval archive hidden in a Cairo synagogue. Their stories intertwine in this spellbinding novel of how technology changes memory and how memory shapes the soul.