Fewer people have been to the deepest part of the ocean than have been to the moon. Even now, the vast majority of this wilderness - which covers over 70% of the planet and forms its largest ecosystem - has never been seen by human eyes, let alone explored or investigated by scientists. Yet our oceans contain perhaps 90% of all life, and the physical and biological processes within it are critical to supporting our existence on Earth. Professor Alex Rogers has spent the past 30 years studying life in the deep ocean. In this book, he takes us on an epic and utterly unforgettable voyage to an alien world, and brings us right to the edge of what is known about our oceans today. Introducing us to glittering coral gardens, submarine mountains and a range of bizarre and breathtaking sea creatures, many of which he discovered first-hand, Rogers not only illustrates the ocean's enormous and untold impact on our lives, but also shows how we are damaging it catastrophically through pollution, overfishing, and the insidious and global effects of climate change. Imbued with the author's infectious sense of wonder, and replete with stunning photography of underwater life, The Deep is a magisterial study of a world we are only just beginning to understand - and a profoundly hopeful call to arms for us to reshape our relationship with it, before it is too late.