"An unforgettable novel of courage, chemistry, and female solidarity in a casually violent, misogynistic world."--The Horn Book, starred review

Early seventeenth-century Rome . . .

For as long as she can remember, Carmela Tofana has desperately wanted one thing: to be a part of La Tofana's, her mother's apothecary in Campo Marzio, Rome. When she finally turns sixteen, she's allowed into the inner sanctum: the workroom where her mother and two assistants craft renowned remedies for their customers. But for every sweet-smelling flower extract in the work-room, there's another potion requiring darker ingredients. And then there's Aqua Tofana, the apothecary's remedy of last resort. In all Carmela's years of wishing to follow in her mother's footsteps, she never realized one tiny vial could be the death of them all.