When Timothy Garton Ash graduated from Oxford in 1978, he went to live in Berlin, ostensibly to research and write about Nazism. But once there, he gradually immersed himself in a study of the repressive political culture of East Germany. As if to return the favor, that culture--in the form of the dreaded East German secret police, the "Stasi"--secretly began studying him. As was Stasi's practice, over the years its study produced a considerable paper trail. After the fall of the East German communist regime, a government apparatus was established to allow those targeted to see their Stasi files, and Garton Ash discovered and pored over his. He then set about to interview the people who made this gross intrusion possible, the several case officers, and the numerous regular-citizen informers. The result is nothing short of a journey into the darkest recesses of the totalitarian mind, taking its place honorably alongside 1984 and Darkness at Noon.