Deep in the desert on the border between Utah and Arizona is a hidden world within modern America. Colorado City is home to the Fundamentalist Latter Day Saints... the largest polygamous community in America. Here, a year-long investigation by ABC News reveals a town of 10,000 ruled by a man behind bars. Warren Jeffs, their leader and prophet, was sentenced to life in prison last year. But his people continue to accept his edicts as law. Over the past year, he has destroyed families by excommunicating dozens of men and women. Men, women, even teens have been forced to leave their families and the only life they have ever known. 20/20″ follows one family: a mother, six daughters and a son, on their path to freedom and as they struggle to survive in the outside world they've been taught will be their damnation. Amy Robach's report airs on "20/20," FRIDAY, NOVEMBER 23 (10:00 - 11:00 pm ET) on the ABC Television Network. VIDEO: Man Searches for Mom, Sisters After Dad Banished by Warren Jeffs and FLDS Carlos Holm confronted church leaders he suspected of hiding his mother and sisters. STORY: Jailed Polygamist Leader Warren Jeffs Issues Hundreds of Orders From Prison STORY: From Prairie Dresses to Ear Rings: Mother and 6 Daughters Leave Warren Jeffs" FLDS for New Life