In Invisible Slaves, W. Kurt Hauser discusses slavery around the world, with research and firsthand stories that reframe slavery as a modern-day crisis, not a historical phenomenon or third-world issue. Identifying four types of slavery—chattel slavery, debt bondage, forced labor, and sex slavery—he examines the efforts and failures of governments to address them. He explores the political, economic, geographic, and cultural factors that shape slavery today, illustrating the tragic human toll with individual stories. Country by country, the author illuminates the harsh realities of modern-day slavery. He explores slavery's effects on victims, including violence, isolation, humiliation, and the master-slave relationship, and discusses the methods traffickers use to lure the vulnerable, especially children, into slavery. He assesses nations based on their levels of slavery and efforts to combat the problem, citing the rankings of the United States' Trafficking Victims Protection Act. He concludes with an appeal to governments and ordinary citizens alike to meet this humanitarian crisis with awareness and action.