"Patient X", the "Messiah" in the narrative, is found in an unnamed city in the middle of a war zone in the Middle East suffering from total amnesia. The first half of the book takes place there. But while X knows nothing about himself, he has clairvoyant powers to read minds and feel total empathy for anyone around him. Escaping from an army hospital where he witnesses torture, he meets Leila, a local photojournalist, who takes him in. They fall in love and marry. Leila is pregnant when X reads the mind of a would-be terrorist and prevents a suicide bombing at the city flower market. But chased by jihadists, he is struck by a truck and loses his recent memory including any idea of Leila and his life there.
He awakens as Jacob, returns to his former life in San Francisco, starts a new business and begins to date Sara. A few chapters later, Leila finds him and gets a job as his secretary. She has lost their baby and wishes only to be near Jacob, who sadly does not recognize her. When Jacob and Sara become engaged, Leila is devastated and returns to her home. Slowly Jacob's memory and his powers of empathy and clairvoyance begin to come back. He breaks off with Sara and flies to the city where Leila lives not knowing yet who he's looking for.