Neuropath is a psychological thriller written by R. Scott Bakker and first published in 2008. It follows the Point of View of Thomas Bible, a psychology professor, who is recruited by the FBI in order to help them track down his best friend Neil Cassidy, a neurologist in the employment of the NSA, who has gone rogue and is apparently abducting people and re-wiring their brains as part of an elaborate attempt to demonstrate the illusory nature of the self and much of consciousness.
Tom's life is not what it once was. His marriage is on the rocks and he is barely allowed to see his two young children. His writing career has stalled with only one successful book, and he is forced to spend his time teaching bored grad students. Then his best friend, Neil, returns from teaching neurology in California and comes back into Tom's life. But all is not what it seems--Neil has been working for the U.S. government cracking the minds of suspected terrorists and has gone AWOL, leaving behind evidence that he has been employing his unique skills on civilians.
Thus begins a terrifying sequence of events as Neil, obsessed with the fact that he can control the human brain, sets out to destroy those who are connected to Tom. And it's only when Neil gets closer to his ultimate target that the full horror of his plan is revealed.