Florence, 1503.  In the heart of the Renaissance, amidst the scent of cypress and the clatter of workshops, Alessandra Martelli breathes life into Leonardo da Vinci’s most fantastical designs.  She’s not merely his apprentice; she’s a visionary, transforming his sketches of mechanical marvels into a clockwork army, a desperate gambit to protect Florence from the insatiable ambition of Cesare Borgia.

Cesare, the ruthless son of a pope, craves Florence’s beauty and its secrets.  He sends his most cunning envoy, the enigmatic Gabriel Fowler, to steal da Vinci’s inventions.  But Gabriel finds himself captivated by a different prize – Alessandra, a woman whose brilliance rivals his own.  Their connection ignites amidst the city’s simmering tensions, a dangerous dance of intellect and desire.  Yet their love is a treacherous game, for Gabriel’s true allegiance lies with the Borgias.  Each stolen kiss is a betrayal, every shared secret a step closer to Florence’s downfall.

Within Alessandra’s workshop, another danger lurks.  Vincent Brandt, her trusted assistant, hides a burning thirst for vengeance against the Borgias, a secret that could shatter Florence’s defenses.  Meanwhile, Samantha Alvarado, a volatile alchemist obsessed with explosive power, arrives in Florence, her unpredictable creations adding fuel to the impending conflict.

As Cesare’s forces tighten their noose, Alessandra uncovers a hidden truth about da Vinci's magic – its terrifying potential for destruction.  Torn between her love for Gabriel, her loyalty to Florence, and the devastating power she wields, Alessandra must make a choice that will determine not only the city’s fate but the future of a world on the brink of transformation. Can she outwit Cesare, control the volatile forces she's unleashed, and ultimately, choose between the city she loves and the man who has stolen her heart?