After the Great Separation, the Earth was left desolate and alone. Now, 4 years later, scientists have returned to their abandoned planet under the policies of the Clean Planet Initiative to restore it, in hopes that humanity might one day be able to return to their home. Ilana works in Michigan's lower peninsula in a small community of scientists with the goals of restoring Earths ecosystems and getting carbon out of the atmosphere. When a fleet of sentient beings, who travel the galaxy like hitchhikers restoring balance to the universe, find their way to Earth, they hope of working alongside the scientists in restoring Earth to its former beauty. Ilana must decide who she can trust, herself, her community, or these strange new beings. Across the world, Cove is alone under the water trying to restore the Coral Reefs to their once held majesty. He is plagued by his loneliness when he meets Eglasia. She offers him the chance to return to humanity, to see his mother again, to be with his family and leave his underwater prison. Cove must decide if he is willing to risk everything he's worked for, for love.