The city of Houston is at the centre of a sex trafficking crackdown. There are more reported cases of child sex trafficking there than any other city in the United States. Across its state of Texas it's estimated at least 80,000 children and young people have been forced into the industry in recent years, usually by people they know. Reporter Yousra Elbagir tracks the heart-breaking search of one mother looking for her daughter, who was trafficked into prostitution when she was just 15. She also follows the private detective and armed bounty hunters trying to rescue teenagers from Houston's seedy underworld.