Face Down upon an Herbal marks the return of Susanna, Lady Appleton, an Elizabethan woman who literally wrote the book on poisons. While her husband is away on a diplomatic mission to Scotland, Susanna is summoned by Queen Elizabeth to work on a new book of botanical decoctions at Madderly Castle. But when the herbalist learns that a pugnacious Scots baron has been found murdered atop the herbal that she has authored, she realizes that there is more to the queen's request. Then the killer strikes again, and strong-minded Susanna takes matters into her own hands and investigates the dastardly deeds. To uncover the truth, however, she must answer some vexing questions: Why are Lord Madderly and the local authorities so quick to blame an outside intruder? How are the deaths linked to a forger who specializes in noble genealogies? Is the murderer part of a treasonous conspiracy against the queen? Faced with a host of suspects who are not as they seem, Susanna must work quickly to find the killer's identity - before she becomes his or her next victim.