During a routine journalistic trip to Greece, James Nestor saw something that left him completely confused: a man dived to a depth of 100 meters (the height of a thirty-story building) on one breath and returned four minutes later unharmed and smiling. Maybe it's a scam? Or do freedivers have superhuman abilities? But the author was surprised to discover the skill of diving deep and not breathing for several minutes in himself. This revelation was the beginning of a great investigation, which Nestor talks about in his book. As he dives deeper into the ocean, he observes whales, seals and sharks - but above all, people who expand our understanding of the possible. The depth, it turns out, is hidden in each of us: incredible abilities are embedded deep in our minds and our genes.