This book follows a cast of intriguing characters, from early mappers such as Marie Tharp, a woman working in the male-dominated fields of oceanography and geology whose discoveries have added significantly to our knowledge; Victor Vescovo, a man obsessed with reaching the deepest depths of each of the five oceans, and his young, brilliant, and fearless mapper Cassie Bongiovanni ;and the diverse entrepreneurs looking to explore and exploit this uncharted territory and its resources. Ocean discovery converges with humanity's origin story;in mapping the ocean floor, scientists are actively tracing our roots back to the most inhospitable places on earth where life began—and flourished. The future of humanity depends on our ability to protect this vast, precious, and often ignored resource.