>> then, they found her. [ screaming ] >> you can't! >> launching a mystery that would divide this family. >> i suspected him from the beginning. >> one daughter thought her stepdad, matt, did it. the others said no way. and matt, he had a theory all his own. >> this is not the first time she's run away, okay? >> had nique taken off and found trouble? >> now you're thinking someone gave her a date rape drug. >> that's a possibility. >> the trail would lead to this house of cameras. >> there is a big server tower that would indicate a large amount of data being stored. >> what they discovered, thousands of hours of tape. >> let me out of this room. >> it's absolutely a torture to listen to. >> and would reveal one shattering truth. >> i got down on my knees and just started crying.