The Wave was a made for TV film. It was based on a book about the alleged experience of a high school class in Palo Alto, California in 1967, whose teacher wanted to explain the rise of the Nazi party to his students. Those who have been involved in an unhealthy church will be able to relate to aspects of it. The quality isn’t very good, but don’t let that stop you from watching.
Years later, a newer version, set in modern day Germany, was released. It is in German with English subtitles.