Few books of scholarship will evoke more horror than this one. Conquest, a British historian and former diplomat (Russia After Khrushchev and Industrial Workers of the Soviet Union, among others) keeps all but his introduction free of emotional content. But the facts are ugly; roughly eight million people were murdered or sent to prison, they were forced to ""confess"" to crimes of which they were entirely innocent, and the whole procedure was enshrouded in a terrifying secrecy. Trotsky had said of Stalin: ""He seeks to strike, not at the ideas of his opponent, but at his skull."" Here Conquest shows him in ""characteristic action"" along with his accomplices Yezhov and Beria. The purge proceeded in what appeared to be random waves and Conquest sees its only possible pattern as ""statistical."" He offers ample data, and his scholarship is unquestionable: evidence comes both from those who have escaped or their manuscripts and from material published recently in the Soviet Union. However, he does make some outsized claims for the importance of his subject. Stalin's shadow is said to loom over the world as the harshest example of cruelty and ruthlessness in this century. Unlike Hitler's terror, according to Conquest, Stalin's persists, though lessened, in the Soviet Union today where terror remains a legitimate political method. Conquest's data, if not his conclusions, make this a useful sourcebook for scholars and amateur Kremlinologists.