1888. A 12-year-old orphan boy, Will Henry, is taken into his service by the brilliant, albeit very reserved, Doctor Pellinore Warthrop. It quickly becomes clear 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 such a profession was doomed to a semi-underground existence. The novel begins with the appearance of a new scourge: headless cannibals devouring citizens with the help of shark mouths located directly on the chests of the monsters. This is discovered when a certain grave robber, under the cover of darkness, brings the doctor his terrible discovery: the corpse of an cannibal, buried in the same coffin with his victim. The determined doctor and the timid Will will have to find and destroy the remaining individuals of this species. The action quickly moves from the laboratory, equipped in the secret basement of the doctor's house, to underground caves in the surrounding forests. The descriptions are breathtakingly naturalistic, the spirit of the late 19th century is conveyed well, and some of the characters seem to have come out of Dickens’s novels. Particularly disgusting is the professional monster hunter hired by the doctor. As a result, they catch the monster, but along the way they find out that the seemingly idyllic surroundings are inhabited by even more dangerous monsters...