Raphael Mechoulam spent a career figuring out how cannabis actually works on the human body, and this film follows that career from a Weizmann Institute lab in the 1960s to old age. Unable to get legal research samples, he arranges to use hashish confiscated by Israeli police, and from it isolates delta-9-tetrahydrocannabinol, THC, the plant's main active compound. Later work with his team locates the cannabinoid receptors built into the brain and identifies anandamide, the body's own cannabinoid neurotransmitter, findings that reframe cannabis as a subject for medicine rather than only recreation. The film also traces Mechoulam's childhood in Bulgaria during the Holocaust, where his father was forced to give medical care inside a concentration camp, and treats that history as the source of his lifelong seriousness about medicine. Interviews with Mechoulam himself carry the science, walking through decades of lab work on a plant that was, for most of that time, simply illegal to study. The film closes on his continued advocacy for cannabis-based treatment, including its effects on epileptic seizures.