Ha'Penny is the second book in my Small Change series. I never meant to write it.
I wrote the first one, Farthing, entirely as a stand alone. It's set in an alternate history where Britain made peace with Hitler in May of 1941, months before Pearl Harbor. The US never came into the war, and the whole European continent is fascist. Farthing is set in 1949, and it has the form of a cosy murder mystery. I'd noticed when reading cosy mysteries that they are actually about premeditated violent death, but they have a way of writing about it that doesn't make it feel that way. I thought this might be an interesting way of writing about fascism. So I wrote Farthing really quickly. in three weeks in the spring of 2003. Normally I research as I'm writing -- this is a good technique that keeps my mind full of the book and gives me new inspiration as I go. But with Farthing because I wrote it so fast I only read Orwell's Collected Essays, Letters, and Journalism as I was writing it, and I had to do a lot of post-book research.
Then one day my post-book research turned into pre-book research for Ha'Penny. Just for fun I was reading J.C. Trewin's Five and Eighty Hamlets, a theatre critic's assessment of eighty-five different productions of Hamlet he'd seen in his career. At the same time, for post-book research I was reading Nancy Mitford's Love in a Cold Climate. Nancy Mitford is one of the notorious Mitford sisters -- a very colourful and unusual lot. One was married to the British fascist Oswald Mosley, another was a communist, another was in love with Hitler, and Nancy was a writer. So I was thinking about women playing Hamlet, as you do when you've just read about eighty-five different men playing him. Then I thought "If there had been a theatrical Mitford sister..." and that's where Ha'Penny came from. If there had been a theatrical Mitford sister in the Small Change universe, and if there had been a plot to blow up Hitler... and that's Ha'Penny.
At the same moment I figured out the third book in the series, Half a Crown. So there never were two books in my mind -- there was one and then there were three. I think I got up and wrote the first chapter of Ha'Penny straight away, and made notes for the rest of it and for Half a Crown.
The three books happen in order, and they have some shared characters who experience plot and character development across the three novels. But they're like series detective novels, where each has its own story. I tried to make them all stand alone, and certainly you can start reading them anywhere. They all share a detective, Inspector Carmichael of Scotland Yard. I realised one day when I was writing Half a Crown that what poor Carmichael wants more than anything in the world is to be a detective in a normal set of mystery novels, where he would solve crimes and tie up all the loose ends and everyone would be happy. Unfortunately for him, he's in my world where everyone is compromised, and most of all him.