Kate Mara plays Smith and David Oyelowo plays Nichols, and the heart of the movie is seeing each of them find some humanity in the other. Neither has any reason to trust, and neither does much to earn trust, either. “I’m a mother!” she says when he first captures her. She wants him to see her as a person, and as a person someone else depends on. But she tells him the truth, that her daughter is not there and will not be returning. And then she lies to him and says that her husband is coming home soon. He asks her for weed, and she says there isn’t any, but he can tell from the way she says it that she is holding something else. It is “ice” (meth) and it is in a small packet she almost could not resist shortly before Nichols captured her.