After the devastating 7.0 magnitude earthquake that struck Haiti in January 2010, reporter Sebastian Walker arrived in Port-au-Prince to cover the aftermath. He ended up staying for more than a year. In the midst of the chaos, a mystery disease began to spread rapidly across the country. In October, 10 months after the devastating quake, the outbreak was diagnosed as cholera. Walker and his team heard rumors that a sewage spill might be the origin of the epidemic and went out to investigate. What they discovered was a global catastrophe.