Last October, spooky overnight radio host Art Bell mysteriously disappeared from the airwaves. Bell's program--which explores all things paranormal--is the nation's fourth most popular radio talk show, heard nightly by more than 6 million devotees; they range from the curiously amused to the furiously paranoid. Bell gave cryptic reasons for his sudden departure, citing "a threatening, terrible event." The conspiracy theories took off faster than a blinking cigar-shaped object in the night sky.

Had Bell been stalked by enemies? Silenced by the state? Abducted by aliens? He returned two weeks later--on Halloween Eve--remaining equally circumspect.

The solution to the mystery turns out to be less otherworldly, but just as weird--a complicated, nasty feud playing out in one very strange neighborhood of the radio dial.

Bell took time off, his syndicator says, because of the stress caused by a slander campaign waged by two former guests on his show and perhaps a network of real-life conspirators. In a lawsuit, Bell claims that his detractors have said--on radio and the Internet--that Bell has been a (1) child molester, (2) pornographer, (3) pimp and (4) convict.

Bell's suit, filed Thursday in Los Angeles, denies all charges and seeks $60 million in damages. The defendants are David Oates--a talk show host who studies "backward speech"--and Robert A.M. Stephens, whose Web site says he is a contractor for NASA. In the suit, Bell says the pair defamed and "cyberstalked" him on Web sites and on Oates's own radio show in April.

"He would spend every waking minute" fretting over the smear campaign, says Kraig Kitchen, president of Premiere Radio Networks, which syndicates Bell's show to more than 460 stations. Eventually it wore Bell down enough that he had to leave the air for those two weeks last fall, Kitchen says.

Premiere trusted Bell's denials but hired private investigators to double-check, Kitchen says. They found "nothing even remotely close to being a pornographer or child molester" in Bell's past, he adds.

Bell did not respond to a request for comment.

Stephens appeared once on Bell's show--heard locally on WWRC (570 AM)--to discuss UFOlogy, the study of unidentified flying objects. Shortly after Stephens began speaking, he and Bell had a dust-up and Bell took him off the air. Since then, Stephens has fired back, including one volley on Oates's radio show.

On April 3, Oates had Stephens on as a guest, during which the latter said Bell had been arrested and imprisoned for selling pornography 20 years earlier, the suit says. Further, he said Bell was involved with "dark matters" relating to the militia movement.

The impetus for Stephens's charges appears to be a two-decades-old incident in San Diego, where Bell was running a video dating service at the time. Police raided the business, which they believed was used to make porn films but which in fact sold singles the chance to videotape themselves for viewing by potential dates. Bell ultimately won a $50,000 judgment against the police department, his Web site says.

Oates has been advised by his lawyer not to comment on Bell's lawsuit.

Oates has frequently appeared on Bell's shows to discuss "backward speech," a process that involves recording speech and playing it in reverse to find supposed hidden meanings. An example on Oates's Web site has a clip of President Clinton addressing the bombing of Iraq. Played backward, Oates says, the clip has Clinton saying: "I am a snake oil terrorist."

Stephens could not be reached for comment, but his Web site appears to welcome Bell's lawsuit.

"I am here, I have steaks on the barbie, and I am [upset]," Stephens writes. "We are wayyyyyy past lawsuits here. Consider, et al. The FBI, FCC, and the Justice Department agrees. If we were in a court room in the next hour, you'd loose. [sic] Sorry."

But there's more to the story than a one-man hatchet job, says Bell's lawyer, Gerard Fox of Los Angeles. It goes much deeper.

Bell first came to Fox in December 1997, saying that he had been slandered by an ex-FBI-agent-turned-radio-host and one of his guests on a shortwave radio show broadcast out of Nashville. The pair--host Ted Gunderson and guest David Hinkson--alleged that Bell had been convicted of an unspecified crime and had bribed a public official to beat the rap. Bell sued them in early 1998 for "unspecified millions," Fox says, adding that he believes the trial will start later this year.

Fox links that assault on Bell with the most recent one. Further, he thinks the amount of resources devoted to attacking Bell--Stephens's Web site displays elaborate, schoolboy-like payback scenarios--indicates that the anti-Bell effort is large and well financed.

"The ironic thing is that Art's show is about conspiracies," says Fox. The lawsuit names 10 "John Does"--unnamed defendants who may or may not be part of the ever-widening anti-Bell cabal.

Finally, there's another twist.

When Bell went off of the air in October, he cited a threat to his family. So far, none of the recent snipes or lawsuits seem to involve Bell's wife, his ex-wife or son, who lives with his ex-wife. But his lawyer says their role in both the ongoing feud and Bell's disappearance will all be revealed shortly. But he wouldn't say exactly how.

So the mystery isn't entirely solved. And Bell remains, at least for the time being, a disembodied voice shrouded in darkness, a steady comfort for the sleep-deprived and those who hear things go bump in night.

CAPTION: Mystery man of the airwaves Art Bell has filed a $60 million lawsuit against two men who he says have defamed him on the air.

CAPTION: Art Bell may have been hovering under the radar last fall, but his disappearance has a very earthly explanation.