At the end of summer 1846, Henry David Thoreau sets off to the north. What begins as a journey by train and steamboat continues on horseback and wagon, by canoe, and finally on foot, gradually transforming into an expedition. His destination: the great mountain, 1,606 meters high, the highest point in Maine - Ktaadn, as it is called in the language of the indigenous people. The path leads through uncharted territory, through a labyrinthine landscape of lakes and rivers and the vast forests of a largely untouched and rugged nature. The boundaries of human habitats are soon crossed, delving deeper and deeper into the wilderness. The last signs of civilization, Native Americans ruined by alcohol, the traces of lumberjacks and fur traders, testify to greed and destruction. Yet Thoreau perceives nature in all its diversity and expanse as unaffected by this.