When a brazen adventuress tries to hire Doc Savage for a secret mission—but won't tell him why—it lights the fuse for one of the most explosive exploits ever to involve the Man of Bronze. Who is Hornetta Hale? Why does she need to rent Doc's private submarine? And who is so determined to eliminate her that they destroy Doc Savage's skyscraper headquarters in the process? From Manhattan Island to the Caribbean Sea, Doc and his fighting crew chase the most violent gang of criminals they have ever encountered in a desperate race to unlock the secret of Phantom Lagoon. Or are they more than mere criminals?