Based on a New Yorker article by best-selling author Jonathan Franzen, the documentary chronicles the rampant poaching of migratory songbirds in southern Europe. Songbird populations have been drastically declining in Europe for decades, and a number of species face imminent extinction. But an intrepid group of European bird-lovers, the Committee Against Bird Slaughter, are risking their lives, waging a secret war to save these endangered creatures.