On a beaver pond in Mid-Coast Maine, a quirky relationship between humans and beavers unfolds each year. The result is a small climate bonanza—a carbon sequestering, water-regulating, species-diversifying wetland. Beavers were hunted to near extinction worldwide by the twentieth century, eliminating, too, the wetlands that once covered large parts of North America and Eurasia. Now, in the twenty-first century, people are inviting beavers back, as vital partners in adapting to climate change. From Rachel Carson’s New England stomping grounds, here is one such story.