When I began writing murder mystery plays, I had the massive advantage of writing for a cast of actors whom I had worked with for several years. I knew their voice patterns, what they looked like and just as importantly, what they were capable of portraying on stage. For me, that was an incredible luxury. When it came to my novel, I knew that I would find it easier to write if I had an idea of what my characters looked like, what they sounded like, how they moved and so on. I'm a visual person - that is my main way of perceiving the world - and as such I 'see' my stories, either as plays on a stage or as films on a big screen. I decided that alongside my storyline, character list and chapter plan, I would also put together a cast. Each character in my novel is based loosely around the thought of a particular actor playing the role of Hartley or Isabelle or some other person from my created world. Note I don't say the characters are based 'on' those actors. Th...