Hoffman (The Right to be Human, 1988), a specialist in modern Jewish thought, presents the first authorized study of the largest Hasidic sect. Almost all New Yorkers are familiar with the Lubavitch, the black-cloaked, black-hatted Orthodox Jews with the famous prayer-locks. Not a Lubavitch himself, Hoffman nonetheless provides a warm overview of this influential group--its membership runs into the tens of thousands--that survived the Holocaust and then migrated to the New World. His account shies away from theology, concentrating instead on Lubavitch activities throughout America--prison outreach in Miami, a school for women in Minneapolis, a campus center in Ithaca, a nationwide campaign to promote menorah-lighting. All these projects orbit around the lower, middle-class community of Brooklyn's Crown Heights, home of the Lubavitch's charismatic Rebbe (head rabbi), Menachem M. Schneerson. Hoffman presents a brief history of the sect, which originated in 18th-century Eastern Europe, but his focus is on the Rebbe's extraordinary erudition and energy. Now 88, the Rebbe frequently delivers four-hour Talmudic discourses and every Sunday has ""flash encounters"" with thousands of the devout, who queue up for a few words of counsel and a crisp one-dollar bill to be donated to charity. This queue is divided by sex, emblematic of the ultraconservative mores that role the sect, and which may trouble some readers (although most of the women interviewed here welcome their well-defined roles). Hoffman concludes by examining the growing Lubavitch presence in Israel and recounting a fascinating intrasect battle over library books that spilled into the New York State court system. A filling slice of religious journalism.