Emmett Hoops was seven when he determined to help save the nearly extinct American chestnut tree. He’s 64 now, but his hope and passion are unabated. In this episode of Constant Wonder, you’ll meet Emmett, but you’ll also hear voices from the past: people who grew up under the leaves of the chestnut tree and who relied on its nutritious nuts—before blight drove it from the American forest around 1940.