Midway through Concussion, the film's already grim focus gets a fiery exclamation point.

As a wild-eyed Justin Strzelczyk, beset by demons in his head, speeds away from his Pennsylvania home carrying $2,700 and a fistful of crucifixes, the movie cuts to grainy footage of the ex-Steeler lineman's black SUV.

Accompanied by the frantic buzz of police chatter, we see the eastbound car racing recklessly through the westbound lanes of the New York State Thruway. Seconds later it slams into a fuel tanker. Both vehicles vanish in a volcanic eruption of angry flames.

"That was dash-cam footage of the actual crash [in 2004]," Peter Landesman, the writer-director of the new film that stars Will Smith as a medical David to the NFL's Goliath, said during a telephone interview earlier this week. "It's a terrible, terrible story."

While objective football fans and others figure to view the docudrama as a cautionary tale, Concussion is a horror story for the NFL, a powerful big-screen rendering of an ongoing tragedy and, for the mighty league, an existential threat.

"If 10 percent of mothers in this country begin to see football as a dangerous sport," one concerned character points out, "that's the end of football."

The dramatic thrust of the Sony film, which opens Christmas Day, is made through the gruesome deaths of tortured former pros such as Strzelczyk; Mike Webster, the Hall of Famer who tased himself to sleep and used Super Glue to reattach teeth; Terry Long, who died after drinking antifreeze; Dave Duerson, who shot himself in the heart so that his brain could be autopsied; and the Eagles' Andre Waters, who killed himself in 2006.

At its core, Concussion is the story of a determined whistle-blower, Bennet Omalu, a Nigerian-born Pittsburgh pathologist played by Smith. Facing constant opposition, Omalu used those deaths to uncover the insidious neurological disease - chronic traumatic encephalopathy (CTE) - that, despite the NFL's fierce denials, he knew was killing and mentally maiming players.

"This movie throws down a gauntlet," Landesman said. "A lot of people were on the wrong side of history on this issue. It's as if we were in 1491 and, according to a lot of people, including the NFL, the world was still flat. And along comes Will as Bennet who's a Christopher Columbus."

Smith admitted that his role and the film forced him to question a game he played briefly at Overbrook High and one that his son, Jaden, now plays.

"I'm a football dad," Smith told Yahoo News earlier. "For me the role was really conflicting."

"We're not focused on a movie, we're focused on continuing to make progress," NFL commissioner Roger Goodell told a small group of reporters in his first (though fleeting) comments on Concussion to the press, earlier this month. "We have incredible progress that has been made, not only in rule changes, but also in what we saw today with materials and protection that will prevent these injuries from happening. From protocols that we implemented, research we are doing, coaching changes we have had, in taking certain techniques out of the game. What you are seeing is an incredible amount of progress and real impact."

A decade or so into the crisis precipitated by Omalu's findings, the NFL may be more popular than ever. And while this film is a gripping indictment of the sport's brutality, it doesn't figure to alter that attraction, in part because the game is not without its appeals. As one character notes, "[It's] mindless and violent. And then it's Shakespeare."

That dichotomy provided a challenge for Landesman, a crusading 50-year-old New Yorker who played football for two years at Brown in the 1980s.

"I tried to make a very strong distinction between the NFL and the game," he said. "I loved the game. I played through high school. I played two years of college. I love athletes and I think the game itself is graceful and powerful.

"But the NFL, like Volkswagen, Dole Fruits, and Boeing, sells and markets a product to a lot of people for a lot of money," he said. "The NFL as a corporation is only interested in the economics. It's not really that interested in the welfare of the players except as how they can serve them."

The docudrama, which spans the period from Webster's 2002 death until the 2006 retirement of commissioner Paul Tagliabue, falls into what is now a classic American film genre.

"It's in that long tradition of David-vs.-Goliath films like The China Syndrome, Three Days of the Condor, The Insider," Landesman said.

And like the best of them, it's got both a compelling hero in Omalu and a convincing villain in the NFL. Though Landesman investigated the subject of concussions intensively, he never sought assistance from the league.

"Didn't ask. Wasn't interested. Didn't need to," he said. "What were they going to say? They certainly weren't going to help me out. They certainly were not going to say, 'Yeah, you're right.' "

The subjects of concussions, CTE, and the cumulative impact of the head trauma that happens in football on virtually every play have long been in the headlines. After decades of refuting any connection between brain disease and football, and after attacking Omalu and his science, the league finally responded by establishing stringent medical protocols.

The concussion protocol the NFL devised calls for a daily monitoring of all players with head injuries. They must progress through a series of proscribed steps and are barred from returning until there's a "demonstrated tolerance of all activities . . . without a recurrence."

But no matter how well-intended its response may seem, as Concussion makes clear, the league resisted fiercely. Omalu and his research were denigrated while the NFL and its medical personnel continued to insist there was no link between concussions and CTE, early onset dementia, or other brain-related illnesses.

It was that denial that drew Landesman to the project.

"I was surprised by how deceptive the NFL has been," said Landesman, a onetime journalist who wrote several cover stories for the New York Times Magazine before turning to film. "They were as deceptive as big tobacco was. They had information about the dangers of concussions for 20 years and kept it quiet. They buried it.

"So as a human being that [ticked] me off. As a storyteller that became part of the fabric of the story about Bennet Omalu. It's a remarkable example of an immigrant's truth-to-power story. It all collided in a pretty fertile way for me."

What surprised Landesman most about the topic was that the problem went far beyond concussions. From Pop Warner to the NFL, anyone playing football endures a series of subconcussive blows to the head. Animals that do the same - rams, for instance - have developed physiological safeguards that protect the brain in violent collisions.

"But the human brain rests unattached in fluid within a fragile shell," he said, "and with every impact it's being jarred and forced into the skull."

In the end, whether viewers are horrified by the subject matter or willing to accept it as an unfortunate sidelight to a wonderful game, it's Omalu's story that likely will entertain and enlighten.

"It's an appreciation of this man who worked so hard at something just to tell the truth," said Landesman. "How could you want to remain willfully unmoved? What a fascinating and important man."

And if, in some unimaginable upset, the movie contributes to the demise or diminution of a sport he loves, how will Landesman feel?

"One of the things I love about watching people watch this movie is that even hardcore NFL fans are able to make a distinction," he said. "They're able to take the movie in and embrace it and even love it and still enjoy the game.

"I just want those people to understand what they're up against. The fact is the NFL cannot be trusted to be fully transparent. So those who see the film will now know what they're watching on Sunday. Now they know what their kids do every time they strap on a helmet.

"After that, as adults, the rest is up to them."