The River Cover Me: Based on the True Life of an FBI Family : Season 1 Episode 22

The FBI assigns Danny to find a young woman in rural Utah who is missing and feared dead. She was part of a polygamist community, where men take multiple wives and everyone avoids contact with the outside world. To infiltrate the clan, the Arnos pose as a polygamist family, but Celeste is none to happy to be Danny's second wife. Eli, the oldest son in the clan (photo attached) falls in love with Ruby, who tries to ditch him one night and stumbles, literally, over a dead body by the side of the river. It isn't the girl the Arnos are looking for, but she appears to have been severely beaten. Barbara then discovers a diary that talks about a shed where disobedient girls are taken to be punished. Can the Arnos discover what's going on before there are any more deaths -- and before Ruby is forced into an arranged marriage with Eli?