Tasked to assist the Verdeau family doctor and their ill but poetic adult heir, Jonathan, Lena chronicles her nights spent working overtime to hide the Verdeaus’ self-destructive tendencies both at home in Boston, and at their Gilded Age mansion, Arrow's Edge—That is until she discovers the Verdeau are the one's responsible for her family's financial struggles, and the firing of her father six months prior.

Using her background in medieval poisons, Lena cautiously devises her own botanical revenge. But when things do not go as planned and her toxic brew gets mistaken by her boss for a hot new drug, Lena quickly finds herself welcomed deeper into the Verdeau's world despite her intentions, and significantly richer in the process.

Tempted by money as much as a dose of power she’s never had before, and with a blossoming flirtation between herself and Audrey, the Verdeau's eldest daughter, Lena must decide how far she’s willing to go, and who she’s willing to put at risk to get the revenge she craves. But the closer she gets to the family, the more she comes to understand that the mysterious illness plaguing Jonathan may not even be an illness at all, and that he has been wronged by his father just as much as she has, and, even worse, that it may be too late to help.