New Zealand is now one of the most lucrative illicit drug markets in the world. Organised crime is about making money. It's a business. But over the past 20 years, the dealers have graduated from motorcycle gangs to Asian crime syndicates and now the most dangerous drug lords in the world – the Mexican cartels. The brutal execution of a husband-and-wife; the undercover cop who infiltrated a casino VIP lounge; the midnight fishing trip which led to the country's biggest cocaine bust; the gangster who shot his best friend in a motorcycle shop: these stories go behind the headlines and open the door to an invisible world - a world where millions of dollars are made, life is cheap, and allegiances change like the flick of a switch.