The other shoe dropped in the Art Bell mystery over the weekend, and the case has gone from amusingly baffling to shockingly ugly.

Last October, the popular overnight radio host--whose Nevada-based show plumbs the depths of the paranormal--suddenly left the air, citing "a threatening, terrible event" endangering his family. He returned two weeks later with no explanation.

Last week, part of the puzzle was solved: Bell sued two former guests for slander, charging them with spreading claims that he was a child molester and pornographer. His syndicator said the stress of dealing with the smear campaign had taxed Bell. But there was more to come, Bell's lawyer promised--the accusations hit the radio host especially hard because they echoed a family tragedy.

On Friday, Art Bell IV--the radio host's 18-year-old son--filed a federal lawsuit against a Nevada school district and a former substitute teacher who is serving a life sentence on sex and drug counts, one of which involved a 1997 sexual assault on the younger Bell. The suit was reported in Friday's Las Vegas Review-Journal.

In April 1998, former teacher Brian Lepley was convicted on several counts of supplying minors with drugs and engaging in sexual relations with them. Moreover, it was charged that Lepley--who carries the AIDS virus--did not inform his partners of his condition or wear a condom.

Though the senior Bell has declined requests for comment, his lawyer--Gerard Fox of Los Angeles--said last week that the combined effects of the smear campaign against Bell and his son's ordeal have been harrowing for the 53-year-old talk show host, who is heard each night by more than 6 million listeners.

"Just being accused of child molestation" is bad enough, Fox said. "Once the public is made aware of what happened to Art and his family, they will completely understand how devastating this has been." Bell is divorced from his first wife, the younger Bell's mother.

Bell's show is syndicated to more than 460 stations nationwide by Premiere Radio Networks, and is the fourth most listened to show after Rush Limbaugh, Laura Schlessinger and Howard Stern. Premiere's president, Kraig Kitchen, said last week that his network has aided the senior Bell, hiring private investigators to help prepare his case against the two former guests.

"If someone is calling you a child molester, it's hard to focus on the events in your life that are work priorities," Kitchen said.

When Bell went off the air last October, the conspiracy theorists--both the merry and the paranoid--immediately conjured scenarios to explain the disappearance, suggesting that Bell, who regularly discusses UFOs, might have been abducted by aliens.

If only the answer to the mystery were that harmless.

Sports Junkies Unlimited

Nothing to trifle with: "The Sports Junkies"--the four guys who parlayed their sports-soaked youth into a talk show on WJFK (106.7 FM)--have signed a deal with Westwood One Radio Network to syndicate their show nationally. The Junkies--John-Paul "J.P." Flaim, Eric "E.B." Bickel, John "Cakes" Auville and Jason "Lurch" Bishop--will expand their weeknight show by one hour, beginning after "The Don and Mike Show" finishes around 7, then continuing to 11 p.m. They will focus on local sports--such as the traditional Monday-night trashing of the Redskins--and take local callers during the first hour. At 8 p.m. Westwood One will take the signal national, to about 50 stations.

The syndication deal came soon after the latest Arbitron ratings report showed the Junkies dominating the Washington market in their time slot. Even though it looks like the Junks have hit the big time--they had to hire a lawyer to negotiate the deal--Flaim says they're not rich and famous yet.

"Cakes is still driving a Saturn," Flaim says.

Space Music, Indeed Use the Force, Mr. Spock: The ever-droll "Marketplace" used the "Star Wars" prequel to play a joke on its listeners. On the evening of the "Phantom Menace" preview, the public radio business report announced it was going to use music from "Star Wars" during its between-segment breaks. At the end of the show, anchor David Brancaccio deadpanned an "apology," telling listeners that the music played had, in fact, been from "Star Trek."

It turns out to be a clever lance pricking the "Star Wars" hype machine, courtesy of Deborah Clark, "Marketplace's" mistress of music.

"I was sitting at home the night before with my roommates, having a 'Star Trek' versus 'Star Wars' debate," Clark confides without apparent embarrassment. "And I thought, 'God, I don't want to do another "Star Wars" story. Wouldn't it be fun to mess with people's heads?' "

She dismissed the idea as too weird even for "Marketplace"--often considered really wacky in public radio's button-down world--but brought it up anyway at the morning meeting the next day. The producers seized on it. The apology was Brancaccio's idea, adding a Pythonesque twist.

As for Clark, 31, the experience made her "really happy to work here, in a place that lets you do this."

Listen to This It's the rare radio commercial that gets a recommendation, but here's one: the Esskay hot dog ads featuring kids posing questions to Orioles third baseman Cal Ripken. The kids, whether they came up with the questions or not, get Ripken to tell interesting--for a baseball fan, anyway--facts that you'd never see in a sports story. For instance: "Why do you wear number 8?" Ripken lets on that 8 was the number he was given in his first major league spring training. Rookies usually are given high numbers; the higher the number, the less likely the player is to make the big-league club. Ripken was so happy to get a single-digit number that he kept it for good luck. In another commercial, Ripken divulges a little strategy: He says that he often interrogates opposing base runners when they reach third, then relays the information to the rest of the team.

CAPTION: Bell's time off the air can be explained in ordinary--but awful--terms.