In 2018 William Sargent finished his fourth book about the politics of erosion on Plum Island and needed to clear his head. So he decided to embark on a series of rambles from New Hampshire to Gloucester, Massachusetts.

His purpose was to investigate the natural history of this beautiful coast. But as so happens when writing about natural history today he ended up discovering a troubling new environmental catastrophe, the die-offs of whales, seals and shorebirds from the buildup of chemicals that have been steadily accumulating in the lungs of the planet--our oceans.