"In 2007, Saket Soni received an anonymous phone call from an Indian migrant worker inside a Mississippi labor camp. He and 500 other men were living in squalor in Gulf Coast "man camps," surrounded by barbed wire, watched by armed guards, crammed into cold trailers with putrid portable toilets, forced to eat moldy bread and frozen rice. Worse, lured by the promise of good work and green cards, the men had desperately scraped together up to 20,000...