A thoughtful, detailed exploration of three small but growing fundamentalist groups within post--Vatican II American Catholicism. The sweeping changes instituted by the Church in the 1960s were not greeted with equal enthusiasm by all American Catholics: A small but highly vocal minority felt the Church had impulsively abandoned its defining precepts. Cuneo (Sociology and Anthropology/Fordham Univ.) examines several distinct groups that have emerged from the ""crisis of identity"" caused by change: moral conservatives, including the militant late-20th-century crusaders against abortion; Catholic separatists, who have withdrawn from the Church and created their own isolationist communities; and Marianists, who seek guidance from the apocalyptic messages of the Blessed Virgin's miraculous appearances. Of these, the last two are perhaps the least understood. The conspiracy theories of separatists--who believe that John Paul II is a false pope, selected by communist forces intent on infiltration--are fodder for ridicule, but Cuneo never mocks his subjects. Rather, he seeks to understand separatism's origins in the seeming vacuum of authority created by Vatican II, which liberalized the priesthood, granted power to the laity, and acknowledged nonpapal sources of truth. Similarly, the author places the Marianists in a context of the demythologization of Catholicism after the Council. Marianism explicitly rejects the deep-sixing of miracles, affirming a divine control of human history. In neglecting to note that many mainstream Catholics have also rejected some of Vatican II's sweeping reforms, albeit in smaller ways, Cuneo runs the risk of missing the larger picture of Catholics' ongoing negotiations with the legacy of Vatican II. Still, this is a winning ethnography of some unusual religious sects.