Transcript for Warren Jeffs' Nephew: 'I Was Brainwashed'
rare look inside the secretive and abusive polygamous sect controlled by warren jeffs. He's behind bars now. But two of his members are speaking out about how they escaped the church. Cecilia vega has the story. Reporter: We're entering the community ruled by warren jeffs. Even though we're on a public road, the message is clear. We're not welcome here. They did that because of us? Yeah. Reporter: Our every move watched. On top of that flag pole, that's a camera. Reporter: And somebody's watching us right now? Yeah. Reporter: Bart and zach are two of one of jeffs' many nephews. And now, his worst enemy. He used god's name to brainwash people. Reporter: You say brainwash, you say these people you grew up with are brainwashed? Yeah. I was terrified of leaving the community. Reporter: They broke free from this flds community where the belief is, men with more wives are more likely to go to heaven. My brother has 9 wives and around 62 kids. Reporter: Now, they're returning for the first time. You're nervous about this? The family will look at us differently like we are the most wicked people on earth. Reporter: They are part of a group of formerly faithful on a mission to help others who may want to get out, too. Is warren jeffs a prophet? No. Reporter: What is he? He's a psychopath. Reporter: It is a real-life drama, playing out on a new tlc show, "breaking the faith." I overheard the girls in church talking about how they wanted to leave the group. I wanted to leave, too. But I was afraid to say anything. Reporter: Why doesn't a girl who is 20, 21 years old, get up and go? They don't know where to go. The only thing they know is the bedroom, the kitchen and the laundry room. That's it. That's all they know. Reporter: They say warren jeffs, serving life in prison for sexually assaulting young girls, still calls the shots from behind bars. There's been no marriages. Reporter: Really? He's the only one that can do the marriages. They can't have kids, either. Reporter: He controls that? Yeah. Reporter: Has anyone had a child since he left? Not that I know of. Reporter: For "good morning america," cecilia vega, abc news, utah. That's chilling stuff. You'll see more of cecilia's report tonight on "nightline."
This transcript has been automatically generated and may not be 100% accurate.