Dr. Andrew Weil leads a group of physicians and scholars through the long history of humans and mind-altering substances, from indigenous ceremonies built around plant medicine to the pharmaceutical drugs of modern medicine. The film moves across cultures and time periods rather than staying in one place, looking at why people have sought altered states of consciousness, whether for religious ritual, healing, or simply escape, and how those motivations repeat across otherwise unconnected societies. Weil and the other experts interviewed avoid taking a side on whether this history is something to celebrate or condemn, instead laying out the range of uses side by side: shamanic practice, ancient rites, and clinical pharmacology. The throughline is continuity, the same basic human impulse showing up in a jungle ceremony and a modern lab. It plays as a survey rather than an argument, with Weil's own expertise in medicine and ethnobotany anchoring the wider tour.