That polygamous Mormon sects can be, in reality, a lot more sinister and disturbing than, say, HBO’s soapy Big Love may not surprise you. But you may be alarmed to learn, from a young man who experienced it firsthand, just how horrifying life within the cloistered compounds of the Fundamentalist Church of Jesus Christ of Latter-Day Saints was under leader Warren Jeffs. Those of us who remember the FLDS “president, prophet, seer, and revelator” from the TV coverage of his 2006 arrest can summon images of a gawky, bland-looking fellow being led around in handcuffs. Lost Boy, an unflinchingly honest, brave and riveting memoir by the FLDS leader’s nephew Brent W. Jeffs, will replace those relatively benign images with far more graphic ones. In it, Brent describes being brutally and repeatedly raped, beginning when he was only five, by his uncle Warren. (Two of Brent’s brothers have also alleged that Warren raped them when they were five or six; one of those brothers, tormented by his memories, later committed suicide.) He evokes the complications and cruelties of life in a “plural” family, where one man, multiple wives, and countless offspring share a home. He depicts the increasingly harsh treatment of sect members under Warren’s leadership and the way young men were heartlessly driven out of the fold by the power-mad “prophet,” as well as these “lost boys” subsequent struggles to build new lives. “I don’t know if polygamy always produces abuse of women and children,” writes Jeffs, “but from my experience, it frequently does.? When women are seen as second-class citizens, I don’t think polygamy can be anything but abusive.” Lost Boy depicts one young man’s struggle to right big wrongs — and to find his way safely home.