In 1874, a group of women opened a “safe house” on the edge of San Francisco’s Chinatown. Because their work disrupted the thriving trade in women between China and America, they faced endless legal challenges and even sticks of dynamite placed on their doorstep. By offering a place for survivors of sex slavery and other forms of servitude to escape to and drawing public scrutiny to the crime, they threatened their century’s existing business model of human trafficking.