Hazel Hughes believes there is nothing remarkable about her, not even her strange ability to heal the sick and injured. Her employer, Doctor Sam MacInnes recognizes her special talent, but because of the difference in their social status, he can't tell her how much he admires her. When a mysterious count arrives in London and reveals to Hazel the existence a twin sister, she agrees to accompany him to the wilds of Romania, where she learns that her healing skills are needed to save her twin's life. Worried for her safety, Sam insists on traveling with her.
Faced with dark magic, malfunctioning automatons, and dangerous magical artifacts, Hazel and Sam learn to rely on each other as they untangle a deadly web of mystery surrounding the count and search for a way to free Hazel's sister from the cursed walls of the Coppergate Tower before time runs out on all of them.