When the police find two skeletons united in an embrace in a Manhattan river, Margo Green, curator of the Museum of Natural History, is invited to collaborate in the investigation, not only for her anthropological knowledge but also for her experience the previous year when she faced a horrendous beast that was loose in the cellars of the museum.
The skeletons show signs of violence and grotesque abnormalities that point to only one thing: the awakening of a dormant nightmare. To the mystery of the skeletons is added a series of brutal crimes.
With the help of police lieutenant D’Agosta, an enigmatic agent of the FBI, Pendergast and an eminent scientist, brilliant Dr. Frock, Margo investigates the origin of the murders. The investigation will take you to a terrifying labyrinth of tunnels, sewers and galleries bordered under Manhattan, where the true secret of the Museum Beast is revealed at last.