1888. Will Henry, a 12-year-old orphan boy, is taken into his service by the brilliant, if very private, Dr. Pellinor Worthrop. It quickly turns out that the doctor has a rare specialty. He is a monstrologist: he studies (and, if necessary, destroys) various monsters, which, it turns out, are found in abundance in New England. In prim Victorian times, a person of this profession is doomed to a semi-underground existence.