The film begins with a powerful montage showcasing football player Mike Webster, played by David Morse, in the midst of his career with the Pittsburgh Steelers. However, fast forward to September 2002, and we find Mike living in his car, grappling with the harsh realities of homelessness and the grips of dementia.
Meanwhile, in a courtroom, Dr. Bennet Omalu, portrayed by Will Smith, is delivering an impactful testimony regarding a murder case. His forensic expertise reveals that the blood on the defendant's hands doesn’t belong to the victim, as the defendant, suffering from hemophilia, was too vulnerable to inflict harm.
In his day job at the Allegheny County coroner's office, Bennet has an unusual practice of conversing with the deceased to glean insights into the causes of their deaths. Here, he interacts with his supportive colleague Gracie, played by Sara Lindsey, but faces antagonism from Danny, depicted by Mike O'Malley. An idiosyncratic trait of Bennet is his habit of discarding used knives, leading him into a humorous debate with his boss, Dr. Cyril Wecht, played by Albert Brooks, about the ethics of reusing instruments.
Bennet's life takes a turn when he is tasked with caring for a young immigrant named Prema Mutiso, portrayed by Gugu Mbatha-Raw. Their relationship blossoms as he extends financial assistance, which she initially rejects, but they soon find common ground and fall deeply in love.
As Mike Webster's downward spiral continues, he seeks help from Dr. Julian Bailes, played by Alec Baldwin. Unfortunately, things take a grim turn as Mike is discovered dead, his body showcasing signs of extreme mental deterioration, including the shocking act of gluing his own teeth back together. As Bennet examines Mike’s brain, he uncovers severe trauma linked to repeated head injuries, which ignites his determination to investigate further.
Through persistent research, Bennet discovers that Mike and other former players like Justin Strzelczyk, portrayed by Matthew Willig, suffered from CTE (Chronic Traumatic Encephalopathy). When Bennet presents his findings to doctors Dr. Steven DeKosky and Dr. Ron Hamilton, they reluctantly acknowledge his claims, though the momentum turns against him when word of his research circulates, leading to hostility from the football community.
Amidst all this, we see the harrowing tale of Dave Duerson, played by Adewale Akinnuoye-Agbaje, as he grapples with his own mental health issues, ultimately leading to tragedy. In a pivotal scene at a restaurant, Bennet confronts Dr. Joseph Maroon, played by Arliss Howard, pleading for the truth to be told to prevent future tragedies within the sport he loves.
The NFL landscape shifts with Roger Goodell (Luke Wilson) stepping in as commissioner, while Bennet faces mounting pressure to retract his statements. Despite the challenges, Bennet and Prema’s commitment to each other grows, culminating in their marriage and their hopes for a family; these dreams turn to heartbreak as they lose their unborn child, a devastating event that drives Bennet to reassess his life.
Fast forward three years, and we find Bennet and Prema now residing in Lodi, California, with their daughter. After tragic news unveils the suicide of Dave Duerson, Bennet is compelled to investigate his brain for CTE. Eventually, Bennet speaks publicly about his groundbreaking research, drawing parallels to the tobacco industry's history of denial.
In a climactic moment, Bennet’s journey culminates in the acknowledgment of his vital contributions to understanding CTE, as he receives an offer for a significant position in Washington D.C. The narrative closes on a somber yet determined note, with Bennet choosing to remain with his family instead, while the NFL faces litigation over its handling of concussions. The closing text reveals the sobering fact that a significant percentage of football players will suffer from CTE, and as all charges against Dr. Wecht are dropped, Bennet Omalu ultimately gains his U.S. citizenship in February 2015, solidifying his legacy as a champion for athletes’ health.
