The long history of the Federal Bureau of Investigation under J. Edgar Hoover is studded with serious questions about the Bureau's professionalism and accountability. Revelations in the recent cases of Wen Ho Lee, Robert Hannsen, and Timothy McVeigh illustrate these misgivings. In Chasing Spies, Athan Theoharis, historian and perhaps the foremost authority on the FBI's record, raises urgent new uncertainties about the Bureau's behavior--and...