When Amelia Wheeler discovers a new species, a glow-worm, near her home in North Carolina, she wants to do all she can to protect it. But climate change, technology, and the sins of the past threaten the nature of their existence. Her estranged brother and sister grapple with finding purpose in their own work, when a sudden death in the family forces them to leave their busy New York lives and return home to the Blue Ridge Mountains, where the three siblings must come together in order to process the traumas of their childhood, or risk losing the things they value most in the world.