The keepers of Scientology have a reputation for mercilessly going after those who dare to criticize the church. So it’s not surprising that Lawrence Wright, while researching the religious movement, received threatening letters from its lawyers and some of its celebrity adherents. They had reason to be worried. The book that Wright produced, Going Clear: Scientology, Hollywood, and the Prison of Belief (Knopf, $28.95), is a thorough and scathing examination of the organization founded by L. Ron Hubbard, who was a best-selling science fiction writer before he became the prophet of a new religion. Wright goes out of his way to be fair, which makes his book’s indictment even more compelling. For all of Scientology’s power and claims of benefits, the book, as a Wall Street Journal reviewer noted, shows the church to be “a charmless system of belief and a small-time organization made large through celebrity and money.”