Combing the backfiles of the U.S. Postal Service and selecting from the memoirs of postal investigators, the author has put together some of the stellar moments of the country's best detectives. The Post Office Department, like the Mounties, always gets their man. The record of successfully solved cases involving mall tampering or fraud ranges from 95.7% to 99.1% according to Miss Denniston. The investigators are given every latitude to check and pursue a suspect-- from poison pen artists to parcel post bombsenders or pilferers. Their stories are all here to prove that truth is stranger than fiction. To underline the superb record achieved by the postal investigators since the 18th century beginnings of the service, the story of the one man of their number to ever betray his trust is told at length. For good organization and clear writing, this beats its only competition on the subject, a poorly written adult book of 1959 -- Makris' Silent Investigators.