Named for the landmark 1989 Parliamentary Act (but not based on a true events), The Children Act follows British High Court judge Fiona, played by Emma Thompson, who must rule on a case concerning the survival of a teenage boy. The boy (Dunkirk’s Fionn Whitehead), who is a Jehovah’s Witness, and just months short of his eighteenth birthday, refuses a life-saving blood transfusion on religious grounds. We spoke to Thompson, her co-star Stanley Tucci, screenwriter Ian McEwan, and producer Duncan Kenworthy about the film, and why they decided to tell this story now.