Florence, 1691. The Renaissance is long gone, and the city is a dark, repressive place, where everything is forbidden and anything is possible.

Knowledge is still the property of the few, and they guard it fiercely. Art, sex and power - these, as always, are the obsessions. Facing criminal charges, Gaetano Zummo is forced to flee his native Siracusa at the age of 20, first to Palermo, then Naples, but always has the feeling that he is being pursued by his past, and that he will never be free of it.

Zummo works an artist in wax. He is fascinated by the plague, and makes small wooden cabinets in which he places graphic, tortured models of the dead and dying. But Cosimo III, Tuscany's penultimate Medici ruler, gives Zummo his most challenging commission yet, and as he tackles it his path entwines with that of the apothecary's daughter Faustina, whose secret is even more explosive than his.