Ulterior Motives - Mark Andrew Olsen

When an al-Qaida email is intercepted, promising a New Year's Day attack on America, it leads to the capture of the group's leader. But even under fierce interrogation, the terrorist clings to his jihadist beliefs and resists divulging anything of the threat. Desperate, the Army resorts to a contingency paper that proposes to break a subject's resistance by inducing a religious conversion. One the top-secret attempt must be masked as an offer of clemency, and must rely on a completely innocent mentor, a so-called witness who is unaware of the project's true aims. They find that witness in Greg Cahill, a disgraced FBI agent who has since turned to Christ and serves in a prison ministry. Lured by an offer of restoration, as well as the lifting of a restraining order that's keeping him from seeing his son, Greg begins an unlikely friendship with a man the entire country despises. Despite himself, he begins to share his faith--yet with a combustible result unforeseen by either himself or his government handlers.

Goodreads: 4.07