"I love Halloween," says the most bewitching member of America's most bewitching band, Fleetwood Mac. "For me it's the best holiday of the year. I always dress up like a vampire or a witch--even more than I do on stage."

None of this should surprise Fleetwood Mac fans. Surrealistically sexy, her body swathed in veils of chiffon, whirling around the stage like a diaphanous dervish. Nicks has always styled herself as the prime purveyor of ritualistic rock. In some circles, of course, her necromantic mannerisms are dismissed as spacey. But to most of Fleetwood's following, Nicks is a true Circe--an eerie enchantress who turns male listeners into swooning swine.

For Nicks, however, Halloween 1980 is particularly pregnant with symbolic overtones. While she's hardly rising from the dead, she is finally emerging from the Fleetwood fold as an artist on her own. After six years with the band, she's just started cutting her first solo album. In a further bid for independence, Nicks, 32, is also writing a book--"the memoirs of Fleetwood Mac, sort of."

Naturally, an inevitable question arises--the same question that has haunted the group since it formed in 1967: Is a break-up pending? It's a weary but not unfair query, since Fleetwood Mac--as former members Peter Green, Jeremy Spencer, Danny Kirwan, Bob Weston, Dave Walker and Bob Welch can attest--has gone through more personnel changes than Fred Silverman's NBC.

The latest split-up stories surfaced last month, even before NIcks announced her solo project, when the group finished its exhaustive, 10-month world tour at the Hollywood Bowl. As it turns out, the current rumors are as insubstantial as their many predecessors.

While acknowledging that the group is possessed by "ghosts from the past," Nicks denies the gossip. Of the present lineup (which includes John and Christine McVie, Lindsey Buckingham and Mick Fleetwood), "no one wants to tamper with the successful formula. There's too much going on between us to want to change."

To underscore its continued cohesion, the group plans to bring out a live LP in the future, and to begin work on a new studio album early next year.

According to Nicks, the crash test of the group's solidarity came with the making of last year's controversial Tusk. "It lasted 13 months and it took every bit of inner strength we had," she says. "It was very hard on us, like being a hostage in Iran, and to an extent, Lindsey [Mac's guitarist and Nicks' former lover] was the Ayatollah. It was a risk, his risk, because it was his concept. We went along with it because we thought it was worth a chance."

As an experimental effort, Tusk hasn't matched the phenomenal sales of the band's preceding LP, the MOR-ish Rumours. "I didn't like the Tusk package," says Nicks. "I didn't like the cover and didn't like the name. I didn't agree with a lot of it. But there's an essence to the album that I totally agree with. It might have been too far away for a lot of people to understand, but I think someday a lot of people will listen to that record and a little light bulb will go off.

"However," she continues, "it won't happen again. We won't do another Lindsey Buckingham album on Fleetwood Mac time. The next album we do will go back to Fleetwood Mac."

Meanwhile, the group is planning to market a videotape made during the recording of Tusk. "It's a documentary on how we work together," says Nicks. "It was so personal we were scared. There's a part, for instance, where Lindsey and I are sitting at a piano, singing 'Angel' and looking at each other. There's a certain thing that goes on between us--it always has and probably always will. but it's there, on the tape! It's incredible--and kind of frightening. You can see all of what's gone on between us for the last ten year."

What's gone on between Nicks and Buckingham, or Nicks and the Starship's Paul Kantor, or the Eagles' Don Henley--or even Elton John, for pity's sake--has also been the subject of rampant rumor. At one point, the gossips had Nicks and Buckingham (who parted ways in 1974) as the parents of a baby girl--actually the child of Mick Fleetwood and his wife, Jenny.

As far as Nicks is concerned, being considered the Farrah Fawcett of rock isn't funny. "I really resent reading about my supposed private life when none of it has ever happened. Actually, I find it hard to meet people because I'm very gullible. I can be hurt very easily, so mostly I live a very quiet life."

Right now she's pursuing that quiet life in her new Camelback Mountain home, just outside Phoenix. Between frequent visits to her parents (her father is a retired Greyhound and Armour Meats executive), Nicks uses the house as a retreat where she can work on new material.

"My living room is pretty much set up," she relates. "I have a gorgeous piano that I just bought, and a lot of recording equipment. I spent three weeks recording all night, every night. I have an incredible living room with wood floors and real high ceilings, so the acoustics are great."

The material accumulated during that three-week recording session is being used for her solo album. The first major artist to sign with Modern Records, an Atlantic Records custom label, Nicks' album will be produced by Jimmy Iovine, who's previously guided Dire Straits and Tom Petty in the studio. Petty and the Heartbreakers backed her up on some of the demo tapes for the LP; a collaboration with Petty, says Nicks, "is very possible."

For nicks, that can only mean the kind of musical sorcery she's been performing since "Rhiannon," her smash single of 1976, which she frequently describes as a paean to "a schizoid Welsh witch."

"I love haunting, haunted melodies," she explains. "I've never been, and probably never will be, a down-home rock 'n' roll songwriter. I try to add that extra, spooky dimension to whatever I do. I want my songs to sort of step a little bit into the bizarre."