In 2009, while thru-hiking the Appalachian Trail, Robert Moor began to wonder about the paths that lie beneath our feet: How do they form? Why do some improve over time while others fade? What makes us follow or strike off on our own? Over the course of the next seven years, Moor traveled the globe, exploring trails of all kinds, from the miniscule to the massive. He learned the tricks of master trail-builders, hunted down long-lost Cherokee trails, and traced the origins of our road networks and the Internet. In each chapter, Moor interweaves his adventures with findings from science, history, philosophy, and nature writing—combining the nomadic joys of Peter Matthiessen with the eclectic wisdom of Lewis Hyde’s The Gift. Throughout, Moor reveals how this single topic—the oft-overlooked trail—sheds new light on a wealth of age-old questions: How does order emerge out of chaos? How did animals first crawl forth from the seas and spread across continents? How has humanity’s relationship with nature and technology shaped world around us? And, ultimately, how does each of us pick a path through life? Moor has the essayist’s gift for making new connections, the adventurer’s love for paths untaken, and the philosopher’s knack for asking big questions. With a breathtaking arc that spans from the dawn of animal life to the digital era, On Trails is a book that makes us see our world, our history, our species, and our ways of life anew.

In the aftermath of tragedy, it’s strange the things you remember. The deafening boom as the house exploded. The paralyzing fear as I searched for my wife. The blinding smoke burning my eyes as I carried her out. But carved into my soul for the rest of my days would be the earth-shattering realization that the woman in my arms wasn’t my wife. Bree and I were the only survivors—not that either of us were truly living after that night. As a single dad with nowhere else to go, I moved into her guest house. And somehow, through the guilt and grief, we forged an unlikely team. It took years, but I watched the gradual return of her smile—slow and life-altering. The two of us could sit outside for hours, talking about nothing, and it filled the massive hole in my chest with new life. I may have carried her out of that fire, but the truth was, Bree saved me. As we healed, the secrets and lies of the past smoldered in the ashes, threatening to ignite again. Our love was born from the embers, and together we would go up in flames.