Against all odds, Constance has found a way back to the place of her origins, New York City in the late 1800s, and sets off on a quest to prevent the events that lead to the deaths of her sister and brother, and stop Manhattan's most infamous serial killer, Dr. Enoch Leng of the seminal Pendergast novel The Cabinet of Curiosities, before his nefarious experiments come to fruition.

Meanwhile, in present-day New York, Pendergast is desperate to find a way to reunite with Constance--but will he find a way before it's too late?