Mark down 8:35 p.m. PT Monday: That’s when the plug will be pulled on John Ensign’s grand delusion, the moment, as the Wachowski brothers might appreciate, that the Matrix is revealed and the grotesque reality becomes unavoidable.

As ABC’s “Nightline” begins a half-hour devoted to the senator’s sex, lies and lobbying scandal, the man walking around as if his career is alive will confront the shocking truth that he has been living in a fantasy world as 5 million people listen to his former best friend accuse him of morally bankrupt and potentially criminal behavior.

Doug Hampton, who began telling his story four months ago on “Face to Face” and has filled in blanks with The New York Times and now “Nightline,” will tell the country the awfully creepy story. ABC may not break much new ground, but the impact of the story is likely to be substantial.

I don’t suggest Ensign will resign. As Joseph Welch once witnessed with a more infamous member of the Club of 100, shame is not a quality that suddenly becomes apparent after years of shameless behavior.

But senators who are not lucky enough to watch “Face to Face” on the Web or didn’t slog through the Times piece last month will see Ensign’s accuser describe what the senator did — and so will many of their constituents who might wonder why Mitch McConnell & Co. continue to condone his actions with their silence. And the “Nightline” report may prod the Senate Ethics Committee, which has begun a preliminary inquiry, and the Justice Department, which may think Khalid Sheikh Mohammed slightly more important than John Ensign, to move forward. Maybe.

Since he disclosed his affair with Cynthia Hampton, a former campaign treasurer, on June 16, Ensign’s attempt to coast through the storm of his own making has been sporadically interrupted by thunderbolts from his ex-lover’s husband. Hampton’s original allegations that Ensign paid the couple an improperly undisclosed severance resulted in the laughable admission by the senator that his parents coughed up $96,000 in “gifts” as part of a “pattern of generosity” from Ma and Pa Ensign.

“Pattern of generosity?” Hampton scoffs to “Nightline” co-anchor Cynthia McFadden in the interview. “Oh, hey, listen, ‘We realize our son’s having an affair with your wife, maybe some money will help.’ It’s ridiculous!”

Almost as ridiculous as Ensign’s benign spin on how he may have importuned companies to hire Hampton and then, according to Hampton, engaged in a conspiracy to break a one-year cooling-off period to ensure his betrayed ex-best friend could make a living while he continued the affair with his wife.

“Why would a client hire Doug Hampton if he didn’t think he would have access to John Ensign’s office?” Hampton will say Monday night. “It’s the only reason I would hire him!”

What do you say about a guy who goes on national television to essentially say he was hired only because of his ties to a U.S. senator — that’s well beyond self-deprecation to self-emasculation — and then, as he did with the Times, admit to a crime (violating the cooling-off law) but says Ensign did, too, by aiding and abetting him?

Yes, he’s desperately out for revenge — as many similarly situated might be. But he’s also probably telling the truth. Or is he? (Some have been vicious in assailing Hampton for his conduct. But only one person in this sordid drama is an elected official.)

Hampton told ABC that he can prove his allegations, but he’ll probably need more than a handwritten note on the severance to do so. Much more serious is that he tells McFadden that Ensign arranged a meeting with a White House official for Hampton despite the cooling-off law.

Although laws may have been broken — we are a long way from that — the seminal issue is that Ensign has been exposed as a raging hypocrite who was a moralizing finger-pointer by day and philanderer by night — the same man who called on President Bill Clinton to resign for similar transgressions.

What would the John Ensign perched on his high horse for so long say about the John Ensign who slept with his best friend’s wife while both were on staff, wrote a cynically pious “Dear Cindy” letter to deceive the C Street moralists he bunked with, funneled $96,000 in severance/hush money to the aggrieved couple, helped the former best friend land jobs with companies needing his legislative assistance and, while potentially breaking laws, reinforced the image of moral degradation too many Americans have of the D.C. elite?

If you die in the Matrix, you die for real. Monday night the plug will be pulled on John Ensign.

Jon Ralston hosts the news discussion program “Face to Face With Jon Ralston” on Las Vegas ONE and publishes the daily e-mail newsletter “RalstonFlash.com.” His column for the Las Vegas Sun appears Sunday, Wednesday and Friday.