"I wanted him to use all his experience and intuition and empathy with people who'd grown up around him in Sheffield and put that into the movie, and I would be [...] the alien force, who was the voice of what science can do, and I would kind of foist these horrible indignities and horrors on these people, and he would try and get them to behave the way they would. So there was an innate conflict in that. We had many shouting matches, really passionate things, totally necessary for doing this."