It sounds like the plot of a thriller movie: unfamiliar men forcibly remove you from your home and put you on a plane without explanation. Before you know it, you're in a remote camp that's supposed to help you recover from behavioural or mental illness. Hundreds of thousands of American teenagers have in fact been to these "wilderness therapy camps". Director Liza Williams' documentary "Hell Camp: Teen Nightmare" explores the history and ideas behind them. She joined us on Perspective.