Nolan noted that actor Liam Neeson, who starred in “Batman Begins” and briefly in “The Dark Knight Rises” as Ra’s al Ghul, was a godsend.
“The great thing about Liam is he can sell anything,” the director said, before recalling one of the film’s earlier scenes between al Ghul (then going by the alias Ducard) and his pupil, Bruce Wayne:
“They’re sitting by the fire and there’s this line I wrote. Liam says, ‘Rub your chest. Your arms will take care of themselves.’ And I pictured Boy Scouts all over the world freezing to death because I just made up this thing. I don’t go camping, I have no idea. And he says it and you believe it!”