The Dark on the Other Side

Linda is terrified; she knows something is terribly wrong in the house and that Something is after her. Unbelieved, she is desperate for any help and escape.
Gordon, her husband, is one of nature's Golden Boys, and has succeeded wildly at every activity...except this. He is showing every sign of desperate anxiety about his wife, and admits to his new friend, Michael, that he's sure Linda is mentally ill, and is agonizingly trying to discover how to help save her from herself.
Michael is a brilliant biographer and the son of one of Gordon's old professors, and has been told he's the only one that Gordon agrees to talk to. While instantly liking Gordon, he recognizes swiftly that there is something terribly wrong in that house, that the atmosphere is sick. Researching the less known aspects of Gordon, he rapidly realizes there is a Jonah Effect: everyone close to him personally has gone mad to some extent, or died. Linda is in several kinds of very real terrible danger, and while it is impossible, it is also real and aggressive. Michael is determined to save her, but can't figure out how---and he needs to do something about Gordon.