As the London Season of 1884 opens, Lady Margaret Savoy wants nothing more than to hide behind the wallflowers and devour “Penny Dreadfuls” to avoid the cruelty of her aunt and cousin. Then, at her first ball, she meets Lord Alexander Rocque and is dragged into a search for the Poisoner, a powerful crime boss who killed her parents. Margaret must uncover his motive and her very identity, as even her own family twists the truth about her heritage and inheritance for their own gain.