"Oswald's Ghost" (PBS, WGBH Educational Foundation, rated TV-PG, $24.99)

"Oswald's Ghost" is an elegantly crafted, 90-minute obituary for the conspiracy theories surrounding the assassination of President John F. Kennedy.

On the one hand, filmmaker Robert Stone (no relation to Oliver) reports that about 70 percent of Americans still disbelieve the official investigation into Kennedy's killing. Veteran conspiracy jockey Mark Lane crows that, unlike the major networks and editorial boards of The Washington Post and The New York Times, "I have been right all along" about the plot to kill Kennedy.

But a more impressive roster of experts, including the late Norman Mailer, Priscilla MacMillan and Todd Gitlin, has arrived at a different conclusion. Edward Jay Epstein, who has criticized the official Warren Report on the assassination, now thinks there was no anti-JFK conspiracy. "As we cover decade after decade, not a shred has come out that would indicate what this conspiracy was," Epstein says. "After 40 years, none of the theories pan out."

I don't know what Stone's agenda was in making "Oswald's Ghost." I understood it as a fairly subtle commentary on time. If there had been more truths to reveal about the Kennedy assassination, time would have yielded them. But it didn't. To borrow the language of "The X-Files," popcult's greatest conspiracy homage of recent time: Maybe the truth was out there all along.

Why is this relevant? Because we again are awash in conspiracy theories. Every major news event attracts an accompanying backwash of debunking, counter-factual argument and conspiracy-mongering. A recent Vanity Fair reported that "many people in London" believe that Prince Philip headed up a conspiracy to kill his erstwhile daughter-in-law, Princess Diana. Really? As if anyone cared.

The main event in contemporary conspiracy-mongering is, of course, 9/11. A few weeks into the fall of 2001, a friend called me from France and urged me to be the first American journalist to report the "truth" about the Sept. 11 attacks. He then sent me French newspaper stories "proving" that no airplane ever crashed into the Pentagon. While it is true that my French isn't what it used to be, I wasn't convinced.

The French have not monopolized this version of events. Not infrequently, I receive e-mails with subject lines like, "Yes, the Bush/Cheney regime deliberately let 9/11 happen."