In the vibrant, cutthroat world of Renaissance Florence in 1478, a young apprentice painter named Matteo discovers his master murdered in their bottega. The only clue is a freshly delivered batch of ultra-rare lapis lazuli pigment, laced with a deadly, untraceable contact poison. Realizing the poisoned paint is meant for a private fresco commissioned by Lorenzo de’ Medici, Matteo must team up with a brilliant apothecary’s daughter. Together, they navigate a treacherous labyrinth of rival guilds, deadly assassins, and the looming Pazzi conspiracy to save the ruler of Florence before the masterpiece is finished.