1348. As the Black Plague ravages Italy, Ginevra di Gasparo is summoned to Florence. Ginevra has a gift - harnessing the powers of gemstones, she can heal the sick. But upon arrival, she is tasked with a much different mission: she must use her collection of jewels to track down a thief who is ransacking Florence's churches for priceless relics. If she succeeds, she'll never be accused of witchcraft again. But as her investigation progresses, Ginevra discovers she's merely a pawn in a much larger scheme. And the dangerous men behind this conspiracy won't think twice about killing a stone witch to get what they want.