Constance Greene has found a way back to the place of her origins, New York City in the late 1800s. She sets off on a quest to prevent the events that lead to the deaths of her sister and brother. But Manhattan's most infamous serial killer, Dr. Enoch Leng, lies in wait, ready to strike at the slightest provocation. Meanwhile, in contemporary New York, Special Agent Pendergast searches for a way to reunite with Constance. Will he discover a way back to her before it's too late?