With the world's highest markups, New Zealand is a top destination for meth. The impact of South American cartels and an Australian immigration law has led to bloody turf wars.

The global black market for organs is thriving. We go inside this vile criminal trade to meet the unscrupulous surgeons and traffickers butchering people for profit.

El Salvador is the extortion capital of the world. Two of the world's most violent gangs, MS-13 and 18th street, use murder, rape and fear to steal a chunk of the country's GDP.