In a Carmelite monastery outside present-day Los Angeles, life goes on in a manner virtually unchanged for centuries. Sister John of the Cross has spent years there in the service of God. And there, she alone experiences visions of such dazzling power and insight that she is looked upon as a spiritual master.

But Sister John's visions are accompanied by powerful headaches, and when a doctor reveals that they may be dangerous, she faces a devastating choice. For if her spiritual gifts are symptoms of illness rather than grace, will a "cure" mean the end of her visions, and a soul once again dry and searching?

This is the dilemma at the heart of Mark Salzman's spare, astonishing new novel. With extraordinary dexterity, the author of the best-selling Iron & Silk and The Soloist brings to life the mysterious world of the cloister, giving us a brilliantly realized portrait of women today drawn to the rigors of an ancient religious life, and of one woman's trial at the perilous intersection of faith and reason.

Lying Awake is a novel of remarkable empathy and imagination, and Mark Salzman's most provocative work to date.