The Dark — Andrew Neiderman

A MASTER OF EVIL...
Los Angeles psychiatrist Grant Blaine's biggest worry should be whether or not his stunning wife, Maggie, will make full partner at her law firm. But his new patient, Jules Bois, pervades his every thought. Despite Bois' delusional boasts of being a master manipulator of evil and death, Grant finds him fascinating, brilliant--and inexplicably privy to his own childhood secrets and adult fantasies. Soon, his marriage begins to crumble under Bois' vile influence, and with each session, Grant feels his authority as a doctor slipping from his grasp....

Maggie is dead scared of Bois' hypnotic grip on her husband. As a criminal defense attorney she wants to respect the sanctity of doctor/patient privilege, but she can't ignore Bois' horrifyingly detailed knowledge of recent deaths in the news. With much more than her marriage at stake, Maggie knows she must call upon all her resources to battle a man who seems to want to possess her husband...MIND, BODY, AND SOUL