Heat
(Book)

"Jesse Warden is at the end of his rope. Imprisoned unjustly (or, at least, for the wrong crime), he spends half his time in solitary confinement and the other half fighting with convicts who want to kill him because he was once a cop. Then, at his lowest ebb, he is offered a way out. To earn his freedom, he must infiltrate a dangerous and reclusive religious cult in the mountains of the Idaho panhandle, a mission that turns out to be a great deal more perilous than his stay in prison. From his first day in the Idaho town, Jesse finds every aspect of life – especially his life – controlled by the strange and dangerous Jack Gene Coldwater, leader of the cult, and his investigation reveals much more than he had imagined." --Goodreads