Watch Sinner for Free: How to Stream the Movie Online at 123Movies. . In a dystopian future where the world has devolved into a pre-industrial state, the Purists rule supreme. The Purists blame technology for all the world’s past ills, and have deemed it to be inherently sinful. A handful of Companions, human-like artificial intelligence, have managed to make it through the apocalypse. They survive the only way they can –by hiding in plain sight.