If the NFL thought they had a concussion problem, things are about to get a bit more blurry for the league as Sony Pictures released the trailer for Concussion, which stars Will Smith, today. Smith stars as Bennet Omalu, the real Pittsburgh forensic pathologist who first discovered a neurodegenerative disease called chronic traumatic encephalopathy (CTE) in the brains of football players. CTE is the result of repeated brain trauma over time and causes depression, dementia, and other behavioral changes.

Omalu’s 2002 finding — and the subsequent discovery of CTE in dozens of deceased football players — has transformed the football world, leading many to question whether football can ever be a truly safe sport. Though the events in the Concussion trailer seem to be somewhat dramatized, Omalu’s discovery is much more terrifying. For nearly a century, doctors knew that boxers who were repeatedly punched in the head could develop symptoms of severe brain damage, eventually leading to dementia. But it wasn’t until Omalu examined the brain of former Pittsburgh Steeler Mike Webster (who’d suffered from severe depression and dementia before dying from a heart attack at age 50) that anyone suspected the same thing could happen to football players.

When Omalu cut slices from Webster’s brain and looked at them under a microscope, he was surprised to see tangled proteins and other characteristic signs of CTE. A year later, Omalu examined the brain of Terry Long — another Steelers legend, who’d killed himself at age 45 by drinking antifreeze — and saw the same picture. “This stuff should not be in the brain of a 45-year-old man,” Omalu later said. “This looks more like a 90-year-old brain with advanced Alzheimer’s.” Yet Webster and Long weren’t alone. Doctors at Boston University‘s CTE Center have since examined 79 deceased NFL players’ brains and found CTE in 76 of them. Many died by suicide or had dramatic changes in personality after retirement. Still, the overall rate of CTE in all players is unknown — it could be an epidemic or a relatively rare problem.

For years, though, the NFL tried its best to hide the evidence about football and brain trauma.

The league established a committee to examine the long­-term effects of concussions on players’ health, but it released findings that were deeply inconsistent with those of other neurologists. Among other things, the committee called concussions “minor injuries,” told players there was no problem with a concussed player returning to a game, and declared there were no long-­term health issues associated with the injuries. Independent researchers sharply criticized these statements.

Omalu expected the NFL to be alarmed at his findings, but as the Concussion trailer depicts, league staff instead tried to discredit him, accusing him of fraud. “They went to the press. They insinuated I was not practicing medicine; I was practicing voodoo,” Omalu later told Frontline. He was barred from league meetings on football and the brain, along with other doctors who later worked on CTE.

When Sony got hacked, it was revealed that a staffer at a public relations firm that represents Will Smith wrote to the makers of the film:

CONCUSSION is going to piss off the NFL. We should not try to pretend otherwise. Moreover, there is no concession we could make short of agreeing to cancel the project entirely that could possibly satisfy them. Our strategy should thus be based on the assumption that we are going to be facing a powerful adversary that may try to prevent the movie from being made—and, failing that, to ensure that as few people as possible see it or take it seriously.

Let’s see how the NFL will respond. Until then, take a look at the trailer for yourself.