In "Deep," James Nestor dives into the enigmatic world of freediving, a realm where human capability stretches beyond the bounds of what is scientifically known. With a journalist's curiosity and an adventurer's fervor, Nestor embarks on a global journey, immersing himself with a unique cadre of extreme athletes and avant-garde researchers. Together, they explore the untouched depths of the ocean, uncovering not just the mysteries that lurk below but also unlocking astonishing insights into the human body and mind. From the haunting calls of distant whales to the astounding physiological adaptations of deep-diving seals, Nestor reveals a parallel universe beneath the waves, challenging our perceptions of the possible. "Deep" is an odyssey that transcends mere underwater exploration. It is a narrative that interweaves the thrill of discovery with profound revelations about our connection to the vast, uncharted waters of our planet. Nestor not only narrates his personal journey of transformation through the art of freediving but also illustrates how this extreme sport is reshaping our understanding of the natural world and ourselves. As he ventures from the shimmering surface to the darkest depths of the Atlantic, Nestor encounters creatures of the deep and pioneers of human potential, each encounter expanding our definition of what it means to be truly alive in a world teeming with hidden wonders.