In a Carmelite monastery on the outskirts of Los Angeles, life goes on virtually unchanged for centuries. Sister John of the Cross has spent years there in the service of God. The only one to experience intense spiritual visions, she is regarded by the other nuns 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. 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?