David Suzuki hosts this survey of the human brain, opening with a detour into archaeology: anthropologist Ralph Solecki's excavation of Iraq's Shanidar Cave, where a Neanderthal skeleton was found with traces of pollen clustered around it, read by some researchers as evidence of a deliberate flower burial and, by extension, an awareness of death tens of thousands of years before modern humans. From there the film moves into neuroscience proper, using interviews and research footage to walk through neurons, synapses, and the brain's capacity to physically rewire itself after injury or new experience. It looks at how early childhood experience, stress, and trauma shape brain development, and at what current research says about the line between nature and nurture. Suzuki also pushes into the harder philosophical territory: what consciousness actually is, and whether subjective experience can be explained by neurons alone. The Shanidar detour gives the film its most concrete scene; the rest builds outward from it into open questions neuroscience still hasn't settled.