Genius could be a matter of unusual brains, or unusually developed ordinary ones, and mathematician Marcus du Sautoy sets out to find which. He meets Tommy, an artist who has covered every surface of his house in intricate drawings, and Derek, a blind autistic pianist who can replay a piece of music note for note after a single hearing. Du Sautoy also tests babies and young children, whose raw pattern-recognition and memory abilities often outstrip adults, and asks why so much of that capacity fades without the right encouragement. Scientists walk him through research pointing to a specific gene linked to learning, and Dr. Paulus demonstrates electrical brain stimulation that measurably sharpens cognitive performance in his lab. Rather than settling on one explanation, the film keeps circling back to nature and nurture together, treating luck and circumstance as seriously as biology. It closes without a clean verdict, leaving genius as something built from overlapping ingredients rather than a single trait anyone can isolate.