Like the beginning of a love affair, a novel starts with a passing interest. I was just finishing The Alchemist’s Daughter when I happened upon Keats’s letters to Fanny Brawne. I was struck by the tragedy of this poet/medical man, dying himself, consumed with love for the girl next door. And this was the unlikely start of a novel set more than thirty years after Keats’s death, during the Crimean War.
Keats’s first biographer was the Victorian golden boy Richard Monckton Milnes.  Then, on the theme of nineteenth century medicine, I remembered Jo Manton’s life of Elizabeth Garrett Anderson, first woman doctor, and from Garrett Anderson was a short step to one of her great supporters, Barbara Leigh Smith Bodichon, an extraordinary woman, feminist, law reformer, artist, journalist, illegitimate cousin to Florence Nightingale.

By now I was hooked. I didn’t remember any reference to an illegitimate cousin in Woodham-Smith’s biography of Nightingale, so I reread it, and no, not a word. But whose name did crop up like a beacon? – Richard Monckton Milnes, no less, the only man Nightingale seriously considered marrying, and whose note of rueful reproach she took to the Crimea: ‘I hear you are going to the East….You can undertake that, when you cannot undertake me…’

Next I dug deep into Victorian medical practices; cholera and amputations became my temporary field of expertise. When a novel is taking shape, everything is relevant and exciting.

This time what struck me in biographies of Nightingale were the struggles she had with other women, the jealousies, intimacies and rages. By now I had my subject. Following my old habit of writing about powerful women acting against the grain of their historical context, my heroine, Rosa, wants to nurse in the Crimea but isn’t accepted by Nightingale. When Rosa goes missing, her timid cousin, Mariella, has to go after her. Leigh Smith Bodichon and Monckton Milnes had given me my themes: women with radical ideas and a huge capacity for love, hidden pasts, the private turmoil within public lives.
I went to Sebastopol and saw the inside of a Russian bastion, stood on the site of the Charge of the Light Brigade, and was staggered by the narrowness of Balaklava Harbour. It was late October and the week that had begun warm enough for T shirts became unendurably cold. In 1854 the British troops had disembarked in hot sunshine, and were instructed to leave their tents and winter coats on board. Within a couple of months they were dying of frost-bite. Their generals, for whom planning appeared to be an anathema, hadn’t even bothered to learn about the Crimean weather.
In the end, instead of being apologetic about my lack of qualifications as a war writer, I took my ignorance as a license to begin. My heroine, sheltered, secure, smug is cosily ensconced in a Clapham drawing room, compiling a scrapbook, when the war starts. But she is drawn deeper and deeper, until, in the words of Florence Nightingale, she is ‘steeped up to (her) neck in blood.’