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The rarely seen world of a polygamist family is documented in "Sister Wives," which follows Kody Brown, his four wives and their combined 18 children trying to live as a "normal" family in a society that shuns their lifestyle. Three of the wives -- Meri, Janelle and Christine -- have worked for years with Kody to develop a cohesive, loving unit, and their marriages produced 13 kids. Then wife No. 4, Robyn, and her three children were added to the family much later, a development that produced mixed feelings, insecurities and uncertainties. Will it disrupt the balance and change the Browns' lives for the worse?