Mariana explores the growing influence of Mexican cartels in the U.S.
Mariana heads to a Southeast Asian hotbed of scamming, where criminal organizations are holding thousands of hostages and forcing them to scam.
Mariana investigates the mysterious next wave of America's opioid crisis.
Mariana travels to Vietnam to investigate reports that young women are being trafficked into China to be sold as unwilling brides.
Mariana investigates the explosive world of armored car heists.
Mariana investigates the growing influence of heavily armed militias.
Mariana investigates the dirty business of bogus addiction treatment.
Mariana investigates the deadly world of illegal street racing.
Mariana investigates the illegal trade in shark fins, going face-to-face with hunters and smugglers and undercover to explore the demand in the U.S.
Mariana van Zeller investigates a dark and very elusive black market, the illicit trade in human organs.
LSD is booming because of the growing faith in its healing power; Mariana hunts for the elusive chemists responsible for making the world's supply.
Mariana embarks on a journey from Africa to the Middle East to investigate how black-market oil is fueling terrorist groups worldwide.
Mariana investigates how the demand for MDMA in the U.S. is threatening to turn the Netherlands into a narco state.
Mariana explores the global surrogacy market to understand how the dream of starting a family is fueling a babies-for-cash black market.
Mariana goes on a mission to understand how personal and financial data is stolen and sold by a shadowy network of hackers and thieves.
Violent crime soars in Los Angeles to levels not seen in 30 years; Mariana journeys into gangland to understand the violence plaguing the city.
Mariana embeds with a crew of crypto scammers who show her how they make millions of dollars in mere weeks.
Mariana investigates underground fight clubs and the push to bring bare-knuckle fighting into the mainstream.
Mariana van Zeller investigates black-market plastic surgery.
Mariana meets the villains behind an exploding online romance scam.
Mariana explores California's booming weed black market four years after legalization.
Mariana van Zeller investigates outlaw motorcycle gangs known as one percent clubs, learning about the bonds of brotherhood that fuel these violent groups.
Mariana exposes a racist underground movement bent on a violent future.
Mariana tracks a smuggling route of stolen cars from the U.S. to West Africa.
Mariana investigates a new breed of cocaine trafficker: lady bosses.
Mariana investigates the criminals destroying the Amazon rainforest.
Mariana explores the billion-dollar underworld of illegal fishing, offering a unique insight into the industry.