Treat Williams

Treat Williams wasn't sold right away when he was offered a guest-starring role on Law & Order: SVU.

"I read the first 10 pages and within the first 10 minutes, I am with two underage girls in a hotel room and I partially expose myself. I called my agent back and said, 'Are you guys sure? Do we want to do this,'" he tells TVGuide.com with a laugh. "My agent said, 'Just read the whole thing and shut up.' So I did and I realized it was one of the most extraordinary parts I've seen in years. It was deeply moving."

Exclusive: Law &Order: SVU drafts Treat Williams for guest spot

Williams' role, as a famous former NFL quarterback named Jake Stanton, is much more than meets the eye. After years of sustaining and playing with concussions, Jake is quietly suffering from chronic traumatic encephalopathy, a degenerative disease that causes dementia-like symptoms such as memory loss, confusion and depression in individuals who have been subjected to head trauma. The disease begins to really make an impact when Jake, a New York sports figure as revered as Joe Namath, is arrested in a prostitution sting involving a 14-year-old hooker. "He is in the early to middle stages of this disorder and we are introduced him to while he is starting to behave strangely," Williams says. "He breaks the law and he's doing things that are not normal for him so Bayard Ellis (Andre Braugher) takes on his case because the argument is that Jake is really not responsible for this behavior."

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For this, Braugher's second of three appearances on SVU, his character must argue for his client's insanity despite the fact that Jake is in denial about his own condition. "Jake's been hiding this from the public for years," Williams says. "He's enraged."

The hardest part of the role for Williams was not simply playing someone suffering from dementia, but playing someone somewhere in between healthy and mentally unstable. "He can be clear-headed for the better part of the day and then slip into a kind of fog and that was the most challenging thing," he says. "They didn't write this as a guy who is really just not with it. This is a guy who seemingly has all of his facilities. As the show progresses, it's revealed that he really is suffering."

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Although Williams was "anxious" about the role, he had plenty of material to draw from. In recent years, 11 deceased football players and four dead hockey players have been tied to CTE, including former NFL players David Duerson, who committed suicide in February and asked specifically that his brain be donated for CTE research, and Corwin Brown, who recently said he will claim in court that brain damage related to CTE caused him to hold his wife hostage. "I played for six years and in college and I had concussions," Williams says. "I suffered concussions when I played Jack Dempsey the boxer [in 1983], so I guess in a way I'm a candidate."

With that in mind, Williams says he has a simple goal for the episode. "Someone said, 'What are you trying to say?' I said, 'I'm trying to get a job as an actor,'" he says, half-joking. "I think that if the show keeps the discussion or the conversation going about this, that will be good."

Law & Order: SVU airs Wednesday at 10/9c on NBC.