Tony Wendice: How do you go about writing a detective story?
Mark Halliday: Well, you forget detection and concentrate on crime. Crime's the thing. And then you imagine you're going to steal something or murder somebody.
Tony Wendice: Oh, is that how you do it? It's interesting.
Mark Halliday: Yes, I usually put myself in the criminal's shoes and then I keep asking myself, uh, what do I do next?
Margot Mary Wendice: Do you really believe in the perfect murder?
Mark Halliday: Mmm, yes, absolutely. On paper, that is. And I think I could, uh, plan one better than most people; but I doubt if I could carry it out.
Tony Wendice: Oh? Why not?
Mark Halliday: Well, because in stories things usually turn out the way the author wants them to; and in real life they don't... always.
Tony Wendice: Hmm.
Mark Halliday: No, I'm afraid my murders would be something like my bridge: I'd make some stupid mistake and never realize it until I found everybody was looking at me.