

Cannabis is the most widely used illicit drug on the planet. To many, it's an evil weed, but to some, it's a sacred herb, even a lifesaver. For decades the global supply was controlled by criminals, but now a quasi-legal industry worth billions of dollars is booming. Visit growers who are leading a horticultural revolution, hear from users consuming for medicinal purposes, go inside the "Green Rush" of medical marijuana in cities across the U.S. and the violent marijuana cartels in Mexico.

The supply chain of cocaine stretches around our world, bringing vast wealth to a few ... and misery to millions. Follow its trail through the eyes of peasant farmers producing cocaine paste, a trafficker tied to Mexican cartels and a 28-year-old crack dealer in Miami's poorest neighborhood. And literally see the true nature of cocaine addiction via revolutionary brain photography in a leading lab in Brookhaven, N.Y.