James McAvoy has a long Hollywood career, but it was never his intention. And now he’s in a film with an impressive acting performance. When filming the upcoming thriller My Son , which will be released in September. McAvoy was never given a script when he was 15. All of the dialogue that viewers will see in the film was improvised in response to the cast’s dialogue. That’s a significant acting challenge. Prior to becoming an actor, McAvoy aspired to be a missionary.