“No, no, not at all,” Franklin said. “We always start something like this trying to keep it as real as possible. We would only ever resort to digital doubles for some stunt moments or things like that. We try to keep them real. That’s the way Chris likes to make a film.”

But then there’s Bane, to be played by Tom Hardy. That might have to be a CGI effect like Two-Face, right? “You’d have to ask Chris. I think he has his plan but we’re at a very, very early stage on the picture at the moment. Obviously Two-Face was an example of fantastic digital prosthetic. They put tracking markers on Aaron Eckhart’s face and replaced one side of his face with CG. So that obviously had to be a digital thing but it’s based on a real performance. Aaron was delivering the lines, giving the performance.”

The parts that are visual effects will be all new. Even though they’ve done Gotham City twice now, Nolan and Franklin like to start from scratch each time. “We try to keep it different every time. There might be a few things, maybe features of Gotham City that will turn up again to give it some sort of visual continuity. Obviously we’ll try and keep some sort of thematic style with that but really, it’s a film in its own right.”

Here’s how secretive Franklin wanted to be. He wouldn’t even admit that Dark Knight Rises was his next film. “Yeah, I’m working on a new film with Chris at the moment, yes.”

So, process of elimination, try to figure out which upcoming Christopher Nolan film this applies to.