The purpose of this handbook is to present basic information about the forty-five most important -- and intriguing -- secret organizations in the United States. Mr. Whalen (Separated Brethren, Catholics on Campus, etc.) uses as a criterion in determining which organizations are ""secret"" not only the obvious one of operational secrecy, but also ritual secrecy. Thus, such candidates as the John Birch Society, which is secretive about its members but has no ritualistic requirements for membership and does not exclude non-members from its meetings, are excluded. On the other hand, such perfectly innocuous organizations as the Knights of Columbus are included because they meet that requirement. In each case, there is a brief historical survey of the organization, along with information about ritual, membership status, organizational aims and activities, etc. Among the societies discussed are the Foresters, Elks, Eastern Star, Freemasons, Mafia, Ku Klux Klan, Odd Fellows, and Rosicrucians. The author writes in a factual and pleasing narrative style, without any attempt to dramatize (or melodramatize) his material. The book is a little too specialized in subject to have much appeal to the general market, but it is a mine of esoteric information that is a ""natural"" for libraries both public and institutional.