Every year more than 100 billion pounds changes hands in Britain illegally. Much of the money is controlled by international criminal networks involved in drug smuggling, human trafficking, and even terrorism. Many British drug dealers outsource the cleaning of their dirty cash to specialist money laundering groups, who collect the money by hand and ensure it's paid out to the right person in the right place - anywhere in the world. These groups operate with a strict hierarchy and a sprawling network of agents all with different roles. In episode two, viewers learn how one NCA team uncovered one such money laundering group, with agents across the country and internationally.