Two headless human skeletons were discovered in one of the canals of New York, and traces of strange teeth are clearly visible on their cervical vertebrae. One of the victims is identified as the daughter of an influential aristocrat, but who owns the other skeleton, whose bones have undergone monstrous deformation? While investigating this case, police lieutenant D'Agosta finds out that recently homeless people living in the underground labyrinths of the city are in constant fear: someone is killing their fellow tribesmen and beheading the corpses. There are rumors about mysterious creatures - wrinklers, who have settled at the lowest levels of the New York dungeon. FBI Special Agent Aloysius Pendergast, who joined the investigation, decides to descend into the underworld of the city to find a solution to the terrible murders...