Combining the insights of a gifted research scientist with vivid tales that are usually the realm of the novelist, Dr. Ronald Siegel lets his readers experience the suspicion, terror, and rage that possess the mind of the paranoid. This is the first book to investigate the actual experience of paranoia and to demonstrate that under the right conditions -- drugs or deprivation, for example -- anyone can be driven into that state. And indeed, eight million Americans already have been. The paranoid inhabits a different realm of being, one that tilts the world ever so slightly. The senses detect these differences and sound mental alarms. Delusions and hallucinations feed on each other, flourishing with amazing speed. The paranoid becomes locked in a new mode of thinking -- viewing life as from a cell. In a dozen case studies, Dr. Siegel follows his patients into the shadow lands where paranoia flourishes -- drug addiction, prison, organized crime, and terrorism. He introduces us to mild cases where there is only a vague sense that something is out there stalking, to those with apocalyptic visions so intense that they shake the foundations of an entire community. We meet the old woman who hears her teeth whispering, the beautiful ballet dancer who falls in love with a shadow, and the cocaine addict for whom the invasion of imaginary bugs was strong enough to kill. This intrepid journey through the mind's dark corridors ends with a reflective coda exploring the suicide of Ernest Hemingway, and there is no better guide than Dr. Ronald Siegel.