In a dark and twisted version of Victorian England, Joanna Wilder moonlights as an unsanctioned apothecary who treats the ailments of her fellow citizens. But there is no cure for her sister's waywardness. When irresponsible Eva disappears five days before her government-arranged wedding, Joanna risks her life and reputation to search for her sister in the treacherous streets of Londo City. She is determined to see Eva married off. Only then will Joanna be free to live life for herself. During her search, Joanna discovers the last place Eva was seen was a medical clinic, run by enigmatic Dr. Gabriel Stone. Something about the doctor isn't right. But Joanna must place her trust in him when she is badly trampled in a riot started by Eva and her rebel lover. As Joanna lies dying, Gabriel is forced to make a life and death decision: let nature take its course or try an untested medical procedure. Secretly in love with her, he undertakes the procedure. Overnight, Joanna starts to change into something not quite human. As Joanna hatches a risky plan to save Eva and her rebel lover from the noose, she uncovers secret after secret about her sister, her own newfound powers and the dark world she lives in-but most of all about the doctor who has played God with her life. She may never forgive him.