The other week, in Nuremburg, I was drifting about the Germanisches Nationalmuseum, as you do. I wasn’t at all thinking about work (✓good) until the sight of something in a glass case brought me up short. Inside was a small anatomical figure, about six inches long: a pregnant woman, carved in ivory, with a detachable abdomen to reveal the foetus and inner workings. Next to it – since in the midst of life we are in death – was  a coffin-shaped carrying box. It didn’t take much of a leap to land back in a world from which I’d only recently escaped – 17th century Florence and the work of Sicilian sculptor Gaetano Zummo (1656 – 1701), the central character in Rupert Thomson’s novel, Secrecy.

Compared to the ivory-turner of the Nuremburg piece – Stephan Zick (1639 – 1715) – Zummo thought that little bit bigger. He worked in wax, his figures were sometimes life-size, and he aspired not only to anatomical precision but to artistic composition, too. Whoever commissioned Zick did so, presumably, with education in mind. In Secrecy, Cosimo III, Grand Duke of Tuscany, pays Zummo to make a wax figure – life-size and very secret – that is both more and less than educational.

Florence at this time is in the grip of moral repression. Everyone nurses potentially damaging secrets. Rumours can be just as dangerous, and the Medici court is a seriously bad place in which to be exposed. Zummo has travelled through Italy over the years to keep one step ahead of his own past. And Faustina, an apothecary’s daughter and Zummo’s mysterious lover, carries the most dangerous secret of all. In the background, waiting for Zummo to slip up, is Stufa, a deeply sinister Dominican monk. The drama is played out in a finely recreated Florence of beauty and menace where, if you take the backstreets, you’ll never be more that six feet from a stiletto.

Secrecy came out in March to considerable and deserved applause (click here for the Guardian’s review) and I was a little surprised not to see it on the Man Booker long  list. The radio version starts 26 August at 10.45 pm on Radio 4.

With so many layers of concealment and hidden meanings to tackle, this was without doubt the trickiest book I’ve attempted to abridge, so I was glad to have producer Ros Ward’s forensic eye going over the scripts. The story is told by Zummo as if recounted to Marguerite-Louise d’Orléans, long-estranged wife of the Grand Duke, with prologue and epilogue voiced by Marguerite-Louise herself. Owen Teale does a fine job not only to drive the narrative and characterise the assorted cast, but to give Zummo himself passion and humanity, without which, in our much-shortened version, he might seem just a tad creepy. If I had to pick a favourite episode, it would be the last, in which Owen brings Zummo’s tale to its dramatic end, before Greta Scacchi, superb as Marguerite-Louise, gives the story a last, beautiful twist.

Listen to and enjoy this tale of love, concealment, art and just a little murder. And then, if you haven’t already, please read the book.