An awe-inspiring portrait of the mysterious world beneath the waves, & the men & women who seek to uncover its secretsFor all of human history, thedeep oceanhas been a source of wonder & terror, an unknown realm that evoked a singular, compelling question:What’s down there?Unable to answer this for centuries, people believed the deep was a sinister realm of fiendish creatures & deadly peril. But now, cutting-edge technologies allow scientists & explorers to dive miles beneath the surface, & we are beginning to understand thisstrange & exotic underworld: A place of soaring mountains, smoldering volcanoes, & valleys 7,000 feet deeper thanEverestis high, where tectonic plates collide & separate, & extraordinary life forms operate under different rules. Far from a dark void,the deepis a vibrant realm that’s home to pink gelatinous predators and shimmering creatures a hundred feet long & ancient animals with glass skeletons & sharks that live for half a millennium—among countless other marvels.Susan Caseyis our premiere chronicler ofthe aquatic world. ForThe Underworldshe traversed the globe, joining scientists & explorers on dives to the deepest places on the planet, interviewing the marine geologists, marine biologists, & oceanographers who are searching for knowledge in this vast unseen realm. She takes us on a fascinating journey throughthe history of deep-sea exploration, from the myths & legends of the ancient world to storied shipwrecks we can now reach on the bottom, to the first intrepid bathysphere pilots, to the scientists who are just beginning to understand the mind-blowing complexity & ecological importance of the quadrillions of creatures who live in realms long thought to be devoid of life.Throughout this journey, she learnedhow vital the deep is to the future of the planet, & how urgent it is that we understand it in a time of increasing threats from climate change,...