A disciplined and sexually driven man forces his family to stay isolated in their home in order to protect them from the “evil nature” of human beings.
This is quite a brilliant fictional recreation of a true story that took place in the 50s. A man keeps his family locked in their house to protect the purity of his wife and 3 children. It's like watching a train wreck in very slow motion. For modern reference, it's somewhere between Black Swan and Dogtooth, although it predates both of those.