First-century Rome is not the quiet, orderly city that it pretends to be, and in this environment, a very clever private informer can thrive. The daughter of Marcus Didius Falco, Flavia Albia is a chip off the old block. She's taken over her father's old profession, and, like him, she occasionally lets her love of a good puzzle get in the way of her common sense, but she always sees the case through.

Over on Rome's Quirinal Hill, naive young Clodia Volumnia has died, poisoned by a love potion obtained from the local witch, Pandora. In her sixth investigation (after The Third Nero), Flavia Albia soon learns that Pandora carries on a trade in herbal beauty products while keeping hidden her much more dangerous connections. When a friend of Flavia's own is murdered, things become serious, and she is determined to expose as much of this clandestine trafficking in murder as she can—beginning with the truth about the death of little Clodia.