In the book, D'Artagnan doesn't actually become an official Musketeer until quite near the end, and we make quite a big thing about that. I won't give too much away, but when he finally does make it, they're not going to make it easy for him. That never changes.

The thing about villains is that villains always have their own logic, and they don't necessarily see themselves as villains. Richelieu is not a villain, in his own mind. He's doing what he needs to do.

The situation that women were in, at the time, was something that Dumas doesn't really go into, but it's a great subject to look at. It's a great genre because you can do a lot. Sometimes in thrillers, you can really explore things, and it's the same in this genre.

You're always looking to make it a bit fresh. I want to make sure people are constantly surprised and interested, and we're always talking to the directors about that. It's a big challenge to find people that can do it.

It's not fundamentally different to any other genre, that action is a particular thing. Being able to do action sounds like it should be straightforward, but it really isn't. I always want the action to be witty. I don't want it to be merely routine.

You do see a few people and you are thinking of how that chemistry is going to work, but it's not really fair to put people who are auditioning together in a room. You have to make that judgement yourself, and that's partly where the casting director is so good. It was that blend that we were looking for.

The BBC came to me and they wanted to adapt the book [Three Musketeers] again, in the straightforward way, and I said no to that. I didn't want to do that. But what I did want to do was have a real look at the adventure genre because I thought it was ripe for reinvention.