Former Special Forces soldier Jason Fox travels through South America, investigating the cartel strongholds of Mexico, Colombia and Peru to lift the lid on their brutal worlds. What kind of lives do their members have, what does their work involve and how do they continue to evade the law? Jason begins in Mexico, where he meets members of the Sinaloa cartel - including killers and ex-assassins - witnesses brutality first hand and finds himself in the middle of a turf war as he tries to get to the bottom of how they operate

In this episode, Jason visits Colombia - where the global narcotics industry began. Colombia remains one of the biggest traffickers of cocaine on the planet. Jason travels to Buenaventura, a port area through which an estimated quarter of the world's cocaine is smuggled. It is a world of extreme violence, in which Jason meets an active assassin who is deeply troubled by what he does. There's also a look at the ingenious new methods for smuggling devised by the cartels. And on a visit to Medellin, Jason meets Popeye, close friend and chief assassin for Pablo Escobar - a man with 257 kills to his name.

Jason Fox travels to Peru. He heads for a remote, treacherous spot in the foothills of the Andes known as Cocaine Valley, where hundreds of tonnes of cocaine are produced each year. Deep in the jungle, under cover of darkness, Jason meets one of the valley's most renowned cocaine chefs, who prepares pure cocaine in his hidden pop-up lab. Jason has to make a swift exit hidden in the back of a pick-up truck. Jason joins a group of young drug carriers on a dangerous trek out of Cocaine Valley. He also joins an elite police unit on a helicopter raid to destroy a jungle lab. But with the cartels quick to adapt and reorganise, is this strategy having any real impact?