Seven years ago and seven miles below the surface of the Pacific Ocean, Dr. Jonas Taylor encountered something that changed the course of his life. Once a Navy deep-sea submersible pilot, now a marine paleontologist, Taylor is convinced that a remnant population of Carcharodon megalodon-prehistoric sharks growing up to 70 feet long, that subsisted on whales-lurks at the bottom of the Mariana Trench. Offered the opportunity to return to those crushing...