From the records of investigative agencies (F.B.I., G-2, O.N.I., etc.) this is the built-up and filled-in picture of Japanese espionage in the United States and Hawaii, from 1932 on. The author of Passport to Treason (P. 161, 4/1/43 Bulletin) which detailed German activities, gives an overall picture of the Japanese machinery and its close tie-up with German spy systems, of the threads that were picked up, followed and proven to be part of the tragedy of Pearl Harbor, of laboriously won knowledge of the major schemes of the Japanese before that debacle. A last chapter on possible sabotage from Japanese too easily released from internment camps here shows the need of tighter surveillance now. A gigantic jigsaw -- this has all qualifications of a thrille.