Tully discusses several of the better-known investigations by the FBI since WWII, and also flips through files on Dillinger, Machine Gun Kelly and German fifth columnists. Underlined is the tedium of such investigations and the fact that the FBI is an investigatory agency rather than a police force. There is no discussion of the overlapping functions of the CIA and FBI, but J. Edgar Hoover emerges as our most dedicated spy-trapper. Better than half the cases discussed have been treated better elsewhere, including the Rosenbergs, Klaus Fuchs, Sobel and other cases. Among the newer entries are the Frank Sinatra, Jr. kidnapping, the murders of Viola Liuozzo and other civil rights victims, the activities of the Klan, and Southern mayhem generally. Also studied are bank robbers, hijackers and people who blow up airplanes for insurance. Tully manages usually to get at the motives of his criminals, but his colloquial style is several cuts below even the Daily News in its tough-guy brusqueness. His book is a straight commercial quickie, but is never quickened with serious insight.