It's the leading cause of death among 18-45-year-olds in the United States: Fentanyl, or rather M30, a blue tablet 20-to-40 times more potent than heroin. It's a drug that kills, but earns the people who produce it billions of dollars.

For two years, French business professor Bertrand Monnet plunged into the heart of Mexico's most powerful cartel for Le Monde: the Sinaloa Cartel. Camera in hand, Monnet documented, for the first time, every stage of the narcos' business model, from the manufacture of fentanyl in the garages of Culiacan to the laundering of dirty money in the skyscrapers of Dubai.

The images and interviews obtained provide a better understanding of how these ultra-efficient, violent criminal organizations operate.

Dubai connection

In the third episode of Narco Business, Monnet gives us unprecedented access to the inner workings of money laundering in the drug business. He takes us to the offices of a trust company, perched atop a skyscraper in Dubai. It's here that a member of the Sinaloa cartel will meet with financial advisors to ask him about laundering millions of dollars from fentanyl trafficking. Monnet finds that, to eradicate trafficking, it is necessary to fight against offshore havens, the financial black holes that the cartels rely on to launder their money.

Watch the third episode of Narco Business: Dubai connection

Editor's note: voices and names have been anonymized.

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