After unwittingly poisoning King Louis XIV, alchemist Mirabelle Monvoisin is forced to see her mother's Shadow Society in a horrifying new light: They aren't the heroes they've always claimed to be, but murderers. Herself included. Mira tries to ease her guilt by brewing helpful curatives, but her hunger tonics and headache remedies cannot right past wrongs or save the dissenters her mother vows to purge. With the Sun King and half the royal court dead, royal bastard Josse de Bourbon's only objective is to keep his injured sisters and the petulant Dauphin alive-until his path collides with Mirabelle's, and he finds an ally in his once sworn enemy. They form a tenuous pact to unite the commoners and nobility against the Shadow Society. But can a rebellion built on mistrust ever hope to succeed?