One of my great joys is writing dialogue. This week on the water Give me two characters, and a dispute, and I’ll happily invent a two page ding-dong scene in no time at all. Add another character, and things get a little trickier – but as long as you can establish three slightly divergent opinions, writing that conversation should, in theory at least, be no more difficult than writing a two-hander. But let me set you a more demanding assignment. Or at least, let me describe the demanding...