The Vatican, admittedly, is a place of mystery; and in no part of that antique institution is the fog of enigma more impenetrable than in the Treasury of the Holy Roman Church. Occasionally, a hint of ecclesiastical finances appears, say, in Time magazine, or in one of Avro Manhattan's hardcover diatribes; but, for the most part, no one knows how much money or property the Vatican controls, and the Vatican, for its part, is not about to tell. For the first time, a large part of the story is revealed in this book. Mr. Lo Bello, an economic writer for the Paris Herald Tribune's Economic Review and a former correspondent for Business Week, by virtue of a long period of intensive and expert digging, interviewing, and observing, sketches an authoritative portrait of a financial power which is nothing less than awesome in its countless ramifications into such non-ecclesiastical disciplines as the manufacture of plastics, the technology of electronics, speculation in real estate, etc. But Mr. Lo Bello is not necessarily a muckraker. He is careful to record that the Vatican treasury is ""regularly drained"" in the cause of good works. He wishes merely to certify to the existence of a fiscal behemoth the reality of which the world only dimly suspects. That he succeeds so well is a tribute not only to his journalistic perspicacity but also to his wit, style, accuracy and objectivity. Such success will not necessarily endear him to the hierarchy of the Church, but it will ensure that Vatican Empire will be at the center of a controversy which will rage long and far.