15th-century Florence: where the river runs red with slaughterhouse blood and bronze statues glow in every square. Into its fold comes a young Leonardo da Vinci. Wayward and dreamy, he is different from the other artist's apprentices, drawn to what passes behind veils of steam in the baths and along the moonlit banks of the Arno.

Such habits have long belonged to Florence, but they carry risk in a city where anonymous accusations slipped into letterboxes destroy reputations overnight. Alongside Leonardo, two men pursue their own forms of immortality: Francesco Salviati, a priest willing to endure any degradation in the name of salvation, and Lorenzo de' Medici, heir to a great banking fortune, for whom wealth proves a shifting, uncertain thing.

Weaving together these three lives, Florenzer is a sensuous and richly imagined portrait of a city that paints over its own decay; where an untested artist, not yet marked by greatness, will dare to follow his most unholy desires.