The industry lied. The documents told the truth. For decades, tobacco companies -- and their hired-gun law firms -- insisted that cigarettes didn't cause cancer. That nicotine wasn't addictive. That the same upstanding corporate citizens who brought the world Joe Camel would never, ever peddle dangerous drugs to children.

Of course, this was all smoke.

They knew. They knew all along. And we know they knew, because there's an entire library of proof. When states sued the nation's four largest tobacco companies in the 1990s to recover an estimated $246 billion in public health costs, the legal discovery process uncovered millions of internal industry papers and memos -- many detailing a long, sordid history of research suppression, bogus science production, sleazy lobbying and deceitful, manipulative marketing, incriminating dispatches from a 30-Plus Year's War to keep the American public puffing despite mounting evidence that smoking kills.

When it comes to concussions and brain damage, what's hiding in the National Football League's files?

No one knows. No one but the league, that is. And if the proposed $765 million settlement of a federal class action lawsuit brought against the NFL by more than 4,500 former players is any indication, league commissioner Roger Goodell and company very much would like to keep it that way. In agreeing to a tentative deal that will bar both current football retirees who decline to opt out and all future pro players from pursuing concussion claims, the league is set to dole out what former NFL Players Association present Kevin Mawae describes as "hush money" -- a hefty payoff to prevent discovery, and with it, the potential unearthing of damaging facts.

Under the settlement, former New York Jets team doctor and current NFL medical advisor Elliot Pellman will never be deposed under oath.

The research correspondence of the league's discredited, controversial Mild Traumatic Brain Injury committee will never come to light.

Former NFL commissioner Paul Tagliabue -- who once dismissed concussions as a "pack journalism" issue and oversaw a league push to market tackle football to children -- will never be put on a witness stand.

The league's long relationship with the Washington, D.C.-based law firm Covington and Burling -- a firm, coincidentally, that was eyeballs-deep in planning and executing the tobacco industry's systemic dissembling and malfeasance -- will never be scrutinized.

In essence, the deal will allow the NFL to keep on keeping on, vault shut, admitting nothing, safe behind its messaging curtain, a wonderful wizard of concussion Oz. Or maybe not. While the football world has been focused on retired Miami quarterback Dan Marino's Hokey Pokey approach to the concussion suits, a recent district court ruling in a relatively obscure case involving former members of the St. Louis (now Arizona) Cardinals threatens to expose the league to discovery, regardless of the settlement's outcome. Moreover, the same ruling could put pressure on the league to increase the size of $765 million deal. Unless it torpedoes the agreement altogether.

This is a bit complicated. Let me explain.

Late last year, retired St. Louis receiver Roy Green and two other former Cardinals sued the team in Missouri state court, alleging that they suffer from football-related brain damage and that the franchise failed to warn them about the risks of long-term harm from concussions sustained during play. In response, the Cardinals argued that the case should be moved to federal court, where it likely would be folded into the class action that produced the proposed settlement.

So far, so familiar. Green's complaint mirrors the other concussion suits. Similarly, the Cardinals' rejoinder paralleled that of the NFL, which maintains that brain damage claims fall under the league's previous collective bargaining agreements with its players, and thus are labor law matters that belong in federal court.

Now for the twist: Green sued a specific team. Not the league. His lawyers argued that their case should remain in state court, largely because (a) employers (like the Cardinals) owe duties to employees (such as Green) to maintain a safe workplace and to warn workers about on-the-job dangers; (b) said duties are a matter of common law, arising independently of labor law.

In other words, Green's lawyers argued that the NFL's CBA doesn't matter with regards to concussion claims. And a few weeks ago, the U.S. District Court for the Eastern District of Missouri agreed.

This is a pretty big deal. Well, potentially.

Back to discovery. Think of a war. An insurgency. The NFL doesn't want to fight potential requests to open its vaults anywhere and everywhere, in remote villages and on distant highways, in state courts across the country. It wants a single front. A global peace deal. The proposed settlement provides the latter. Granted, former players can opt out of the deal and pursue individual suits in federal court -- and with them, a shot at discovery. But their position will be significantly weaker. The league likely can afford to outspend and outlast them, to isolate and starve a handful of guerrilla dead-enders.

Green's case is different. It opens a second front in state court, a less-friendly battleground for pro football. And Green's lawyers can begin discovery against the Cardinals right away, no matter what happens with the NFL settlement.

Following Green's example, former players for the St. Louis Rams and Kansas City Chiefs could sue those teams and expect to remain in state courts, joining the discovery battle. In fact, two groups of former Chiefs players led by Albert Lewis and Neil Smith who already have sued the team and had their cases moved to federal court are requesting their suits be remanded to state court.

"We intend to discover the truth," says Paul Anderson, a Kansas City attorney who is part of the legal team representing Green in the Cardinals case and Lewis and Smith in the Chiefs cases. "There's a lot of things out there publicly that are very damming to the NFL and its member clubs. We intend to find out what hasn't been made public, what the NFL has concealed from the players for so long."

Believe it or not, things could get worse for the league. A lot worse. Follow along. As Mike Florio of Pro Football Talk has pointed out, the NFL's initial defense against concussion suits is that there should be no suits in the first place. To the contrary, the league argues, all brain damage claims fall under previous CBAs, which means they should be resolved in arbitration. Not court.

Compared to jury trials involving alleged employer wrongdoing, arbitration tends to be more predictable and less employee-friendly. It's also private. Discovery is usually far less extensive. Evidence generally does not become a matter of public record. Long story short: if you're a corporation with something to hide, you want arbitration. The NFL did. Prior to the settlement announcement, the league asked Anita Brody, the federal judge overseeing the consolidated concussions cases, to send all of the suits to arbitration -- but because of the settlement itself, Brody never ruled on the NFL's request.

Enter the Green case. According to Anderson, the league's arbitration argument before Brody cites the same portions of the NFL CBA (regarding athletic trainers, players seeking second medical opinions, and so on) as the Cardinals' argument before Perry. Perry ruled against the team, finding the CBA to be irrelevant. Although her decision isn't binding beyond the Eastern District of Missouri, it could have what lawyers call persuasive authority -- that is, federal judges around the country, including the Third Circuit's Brody, likely will consider it when ruling on similar questions.

What does this mean for the league? It means that if former NFL players in places like California or New York sue teams over concussions, those suits theoretically could remain in state courts, opening additional discovery fronts. It also means former players and clever lawyers are now more likely to follow Green's lead and sue teams instead of the league, because the mere threat of discovery equals significant negotiating leverage.

Speaking of leverage: The proposed $765 million settlement was born of fear. The NFL feared discovery. Players' attorneys feared that most or all of their cases would be sent to arbitration. Following Perry's ruling, that calculus may have changed. Florio explains:

… the outcome also could result in the plaintiffs in the settled case to quit trying to persuade Judge Anita Brody to approve the settlement, opting instead to proceed with the litigation. If the players in that case secure the same victory Roy Green and others have realized in Missouri, the value of the claims would potentially skyrocket …

The settlement already is troubled. Many observers -- including yours truly -- believe that it's wholly inadequate, too small in size and too limited in scope. Judge Brody has expressed doubts as well, refusing to grant preliminary approval of deal. A group of former NFL players including Alan Faneca and Sean Morey are attempting to intervene in the process, the better to lobby for more generous terms.

You're the NFL. You want this all to go away. If the proposed agreement falls through and federal litigation resumes, you could be stripped of your first and best defense -- and instead plunged into discovery hell. What's a revised settlement worth to you? A cool billion? The $2 billion the players' attorneys reportedly first asked for? Even more?

Alternately, you know that a settlement won't stop Green. It may not stop others like him, either. Discovery hell has shifted to state court. It could be just as hot. Do you bother with a settlement at all? After all, what's the point of paying hush money if people can still talk?

"Theoretically, you should be able to take [the Green] case and apply it to any NFL team," Anderson says. "This is also the same issue that is pending before Judge Brody regarding the NFL's motion to dismiss. So the significance is potentially huge. The effect could be that the NFL -- or at least its member clubs -- can no longer hide behind the CBA."

To borrow a phrase from former CIA director George Tenant -- while continuing our insurgency metaphor -- "discovery is not a slam dunk" . It will take time and money. Lots. Tobacco companies fought tooth and nail against disclosure. They were successful for decades, largely by using -- and abusing -- attorney-client privilege to shelter their most incriminating documents. If push comes to legal shove, expect similar scorched-Earth tactics from the NFL.

Also remember: Green is suing the Cardinals. Not the league. His lawyers should be able to subpoena the team's files. Depose team doctors, too. But will they be able to frisk the NFL itself? Given that Green and his fellow plaintiffs played in the 1980s, will they be able to question the league about its brain trauma knowledge and behavior during the 1990s and beyond, the timeframe for "League of Denial" and what Anderson calls "damming public things?"

A lawyer who has worked on the NFL concussion cases -- no friend of the league, and an admirer of the legal work that went into the Green case -- has doubts.

"I'm not pooh-poohing the decision by the judge or the result," says the lawyer, who requested anonymity. "I think it's a great result. But theoretically, why would it open the discovery doors to the NFL? Can't they just say, 'Look, judge, they can have the team physician that treated Roy Green, but we'll be damned if they look into our files?'

"Let's face it: this is an NFL case about NFL issues, like the concussion committee, Pellman, [Dr. Bennet] Omalu, the disability system, scientific fraud. How do you get to that by saying team doctors and coaches improperly handled concussions? How do you get to those big smoking guns? You don't. You just don't. If someone can show me otherwise, they're a better lawyer than me."

Green's attorneys say they're ready. They won't be intimidated. Their lead lawyer, Kenneth McClain, was the first attorney to obtain a federal court order breaking the tobacco industry's attorney-client privilege defense, forcing R.J. Reynolds Tobacco Co. to turn over 32 "special projects" documents containing evidence that the company knew that nicotine was addictive. Documents obtained through a separate federal court order subsequently showed that the industry's Council for Tobacco Research, founded in 1954, was a front organization producing bogus, lawyer-supervised scientific studies that a judge said were intended "solely to further the economic interests of the industry."

"Our goal is to discover the truth, wherever it is," says Andrew Schermerhorn, an attorney for Green. "If relevant information exists in the files of the NFL, we are confident that the rules of discovery will allow us to obtain it."

How so? Here's a thought exercise. Suppose the NFL tries to restrict discovery to individual teams such as the Cardinals. State courts, team lawsuits, leave us out of it. Could Green's attorneys crowbar their way into the league's files? Yes. Provided the Chiefs lawsuits are remanded to state court, they can depose and subponea former Kansas City team doctor Joe Waeckerle, who also was a member of the league's controversial concussion committee.

Now consider: Pellman ran the concussion committee. He was Tagliabue's personal physician. He also worked for the Jets. Committee members Mark Lovell and Joe Maroon worked for the Pittsburgh Steelers. Former Philadelphia Eagles trainer Rick Burkholder was on the committee, as were Baltimore Colts team doctor Andrew Tucker, New York Giants trainer Ronnie Barnes and Indianapolis Colts doctor Doug Robertson and neurosurgeon Henry Feuer. If other former players follow Green's lead, sue those teams and remain in state court, each man could be targeted. Each is a potential lockpick, a tool for uncovering what the NFL knew and when it knew it.

"I can't say at this stage which doors are open," Schermerhorn says. "But we intend to open and walk through as many as necessary to get at the truth."

In 1994, Phillip Morris chief executive officer William Campbell appeared before Congress. He wore a nice suit. After raising his right hand, he said the following: "I believe nicotine is not addictive." Six other tobacco executives did the same. All were lying. The documents told the truth: as far back as 1961, industry scientists were referring to their customers as nicotine addicts. Five years ago, Goodell testified on Capitol Hill. He wore a nice suit. Asked if there was a link between football and brain damage, he declined to answer, deferring to medical experts and referring to a "medical debate." Did he know better? Did the NFL? Do the league's doctors and documents tell a different, less equivocal story? Thanks to Green, we may be closer to finding out.