Omalu is the real-life doctor who, while working as a forensic pathologist in Pittsburgh, discovered a new and terrifying brain disorder that he named Chronic Traumatic Encephalopathy, or CTE. He discovered it performing an autopsy on a retired Pittsburgh Steeler named Mike Webster. Neither man understands what’s happening to them. Omalu figures it out: the persistent head injuries sustained in football play shake up the brain and causes hallucinations, memory loss, and much more trauma.