A human rights and environmental catastrophe is happening right now, and it's powering everything from smart phones to electric car batteries. Siddharth Kara joins us to expose how China is using modern day slaves, including children, to turn a small patch of the Congo into the world's largest cobalt mining operation. Siddharth shares what he witnessed firsthand from years of undercover research inside the Congo, what life is like for the Congolese who are forced into these mining operations, how China came to totally dominate the world's largest cobalt reserves, and what Americans can do to rectify this terrible situation.

Siddharth Kara is the author of "Cobalt Red: How the Blood of the Congo Powers Our Lives." He is a researcher and activist on modern slavery, an adjunct lecturer at the Harvard Kennedy School of Government, and a Visiting Scientist at the Harvard School of Public Health. Follow him on Twitter at @siddharthkara.