Software prodigy Josie Ashkenazi has invented a programme that records everything its users do. When an Egyptian library invites her to visit as a consultant, her jealous sister Judith persuades her to go. But in Egypt's postrevolutionary chaos, Josie is kidnappe - leaving Judith free to usurp her sister's life, including her husband and daughter, while Josie's talent for preserving memories becomes her only hope of escape. A century earlier, Solomon Schechter, a Cambridge professor, hunts for a medieval archive hidden in a Cairo synagogue. What he finds will reveal the power and danger of the world Josie's work brings into being: a world where nothing is ever forgotten. A Guide for the Perplexed is a spellbinding tale sure to bring a vast new readership to the acclaimed work of Dara Horn.