The #1 New York Times bestselling adventure by Neal Stephenson, sci-fi superstar and acclaimed author of THE BAROQUE CYCLE is now in paperback. Since childhood, Raz has lived behind the walls of a 3,400-year-old monastery, a sanctuary for scientists, philosophers, and mathematicians, hidden from the "saecular" world. Until a higher power, driven by fear, decides it is only these cloistered scholars who have the abilities to avert an impending catastrophe. And, one by one, Raz and his friends, mentors, and teachers are sent forth without warning into the unknown.