In the New York Museum of Natural History, rumors have long circulated about a terrible “Museum Beast” living in the abandoned basements of a huge building. And now these rumors have turned into a horrifying reality: in the museum, two children are killed in brutal fashion, and then the mutilated body of a guard is found. The investigation of these crimes—shocking in their cruelty—is entrusted to police lieutenant Vincent d’Agostine, who at first suspects a maniac is at work in the museum. This theory is supported by a special agent of the FBI, Aloysius Pendergast, who had investigated a similar series of murders in another state. But gradually the terrifying truth comes to light: the Museum Beast exists—and it continues to kill…