Jonathan - or 'Jonah' to his bro - has been one of Nolan's closest collaborators since his short story Memento Mori was adaptated into Memento back in 2000. The pair have gone on to co-write The Prestige, The Dark Knight and The Dark Knight Rises, putting flesh onto the bones of Nolan and David Goyer's story arc. "I'd call Jonah up in the middle of the night and ask, 'How the hell do I do this?'" laughs Nolan of their regular catch-ups, "and he'd give me answers. He's always very generous in that regard. I help him out too, though probably not as much. I'm too busy!" There's synchronicity in their relationship too: Jonathan remembers his brother buying him a copy of The Dark Knight Returns for his 13th birthday. That worked out nicely for both of them.