Mariana uncovers a supply chain of firearms being smuggled into the hands of drug cartels.

Mariana journeys into gangland to understand the violence plaguing LA.

Mariana investigates fentanyl, a contributor to the deadliest drug crisis in U.S. history.

Mariana retraces one of the world's most intractable smuggling routes, following cocaine's path around the world - from the Peruvian jungles, to the Colombian coastline, and to the streets of Miami.

Mariana sets off on a wild journey through California’s black market for weed, which has mushroomed since marijuana legalization four years ago.

Mariana van Zeller follows a meth superhighway from a cartel-run lab in Sinaloa across the border and into the lives of American users.

Mariana explores the billion-dollar underworld of illegal fishing.

Mariana dives into the world of international scamming to understand how it all works.

Mariana meets the craftsmen who make and sell the world's finest counterfeit U.S. dollars.

Mariana attempts to understand the vanity, insecurity and greed that drives steroid use.

Mariana investigates the growing popularity of bare-knuckle fighting.

Mariana travels to Vietnam to investigate reports that young women are being trafficked into China to be sold as unwilling brides.

Mariana van Zeller investigates underground plastic surgery, from motel-room operations to a deadly revelation about Miami’s discount surgery centers.

Mariana meets the villains behind an exploding online romance scam.

Mariana van Zeller investigates outlaw motorcycle gangs known as 1% clubs, learning about the bonds of brotherhood that fuel these violent groups.

Mariana investigates the criminals destroying the Amazon rainforest.

Mariana goes in search of the elusive chemists who make the world's LSD.

Mariana tracks a smuggling route of stolen cars from the U.S. to West Africa.

A look at the complex inner-workings of the global underworld, black and informal markets.

Mariana sets out to understand the ugly business of illicit sex in America.

Mariana exposes the dangers of the growing and deadly ghost guns industry.

Mariana investigates the dark underworld of fraudulent addiction treatment programs.

Mariana investigates the global phenomenon of armored car heists, responsible for some of the most brazen and dangerous robberies in the world

Mariana investigates the global surge in anti-LGBTQ+ violence.

Mariana investigates a new breed of cocaine trafficker: lady bosses.