Part two of two. Guy Martin continues his tour of the country's secret side by trying his hand at a semi-illegal cycling sport, where the goal is to drop down the steepest mountain roads as quickly as possible on modified bikes, using extra weight to go faster. After climbing onboard a drug cartel's smuggler narco-submarine to see how it could be built in a jungle workshop, Guy gets face to face with a drug dealer and former employee of Pablo Escobar