Braiding together personal, collective, and historical explorations of what it means to "go west," Amy Kaler offers deep reflections on the meaning of life, middle age, and climate catastrophe. She explores "ruins" of the human history of the North American settler west--faded hamlets, bunkers, fields of cars, bends in the river--that serve as emblems of hope, generational commitment abandoned by contemporary heirs, faith, hubris, even carelessness. These stops are intertwined with reflections on aging, temporality, and change, making the book feel like a deeply satisfying road trip with a thoughtful friend. Moving from meditative to ardent to sobering in compelling and measured ways, Half-Light shimmers with urgency and suggestion.