Everyone warned Bernthal that Nolan's sets are brutally rigorous. He was delighted. What surprised him was that within Nolan's airtight structure and total vision, he still demanded real creative freedom from his actors — not just allowed it, demanded it. For Bernthal, needing it to be a certain way is the biggest telltale sign of mediocrity. Nolan, somehow, has maximum structure and maximum freedom simultaneously.