Higher peaks in view: The man who wrote Twin Peaks has plans to get weirder. Mark Frost talked to Kevin Jackson about Sherlock and warlocks

SOMETIMES things are not what they seem. Beneath the surfaces of Walter Hill's noisy biker musical Streets of Fire and John Boorman's urban thriller Point Blank are themes derived from the Arthurian cycle and the Grail romances. Ron Howard's Willow and George Miller's Mad Max series both draw on the kitty of motifs provided by The Hero with a Thousand Faces, a scholarly work of comparative mythology by the late Joseph Campbell. And sometimes the inspiration for popular shows can be even more recondite, as in the case of Twin Peaks, now departed from our screens but - as proved by the Japanese craze for Peaks holidays reported earlier this week in The Independent - certainly not forgotten.

As the series grew wilder and woolier, it became clear that someone behind the cameras had been nosing around in some pretty strange areas. It wasn't just the business about 'Project Blue Book' and its UFO research, or Native American legends, or the free-floating thing of evil known only as 'Bob': there were also references to obscure folklore concerning Stonehenge, and, most curious of all, to 'Black Lodges'. This last term seemed as if it must have been lifted from a book you don't expect to find next to the bound copies of Variety on a producer's shelves - the minor occult classic Psychic Self-Defence, by Dion Fortune.

'That's right, that's exactly where I got the Black Lodge from', agrees Mark Frost, who not only wrote most of Twin Peaks but co-produced it with David Lynch, directed some episodes and even - 'reverse nepotism, I guess you'd call it' - cast his father, a professional actor, in the role of Doc Hayward. 'The whole mythological side of Twin Peaks was really down to me, and I've always known about the Theosophical writers and that whole group around the Order of the Golden Dawn in the late nineteenth, early twentieth century - W B Yeats, Madame Blavatsky and a woman called Alice Bailey, a very interesting writer.'

Talk like this has a refreshingly other-worldly sound in the context of an upstairs room at the Groucho Club in Soho, and Theosophy isn't the only hermetic topic Frost brings up. In the course of an hour or so discussing his past, present and future activities, Frost also has occasion to mention the voodoo-related cult of Santeria, ley lines, spiritualism and the work of the popular English occultist Colin Wilson.

It could all seem a bit, well, flakey were it not that Frost is very much in the disarming Regular Guy mode noted by everyone who meets David Lynch, though Frost is notably more forthcoming. It's clear that his fascination for this odd stuff is tempered by scepticism, and that he's more tickled than obsessed by it. If Frost has (as Pauline Kael once remarked of the Australian director Peter Weir) 'a penchant for the major arcana', it's from an interest in off-beat script ideas rather than from any desire to don a pointy hat and turn people into frogs.

There's certainly nothing dreamy or ethereal about his work rates. Since finishing Twin Peaks, Frost has written and directed his first feature film, Storyville (just about to open in the States) completed and sold his first novel (publication due next spring) and collaborated with Lynch on a six- part television series, On The Air, due on our own screens soon. On The Air will come as a surprise to those who remember Twin Peaks chiefly for the stabbings, shootings, beatings and druggings, but will be fun for those who liked the goofiness of Deputy Andy, the squeakiness of Lucy and the general daftness of the Pine Weasel Fashion Show. It is, in short, a sitcom, set in an American television studio in the late 1950s as a live variety show is about to transmit for the first time and things are going horribly wrong. Slapstick, yes, but strange slapstick.

'My father used to work in live television and told us stories about it, and when I talked to David about the subject he just loved the idea of all this backstage chaos, and really took the lead with it. I wrote a lot of the material with particular actors from Twin Peaks in mind - we built up a sort of repertory company - and the humour grew out of the funny parts of Twin Peaks, which are really the parts I'm most pleased with.'

On The Air will, however, probably be the last collaboration between Frost and Lynch for quite a while. Frost took no part in Lynch's prequel film Fire Walk With Me, their partnership Lynch / Frost productions has been amicably dissolved and Frost is about to set up his own company to develop film projects. Some of these sound as if they carry the Frost trademark of applied oddity; others are a little more conventional. Storyville, for example, which opens in America next week, is a relatively straightforward political drama set in and around New Orleans.

'It's based on one or two real- life Louisiana families who went into politics and ran their disticts, or what they call parishes, like private kingdoms, gleefully raping the landscape without restraint. James Spader stars in it, and he plays a young candidate for Congress who comes from this family which has been in politics for generations. He gets involved in a blackmail and murder plot and comes to discover the dark secrets that underlie his family's fortunes. The film was finished a while ago, but the company held it back till now because they wanted to release it when the Presidental campaigns were really hotting up.'

Frost also hopes to make a film from his recently completed novel; it is as yet untitled, though he is hesitating between The Left- Handed Path and The List of the Seven. 'It's set in Britain in 1888, and it's the story of the young Arthur Conan Doyle and the man who will become his model for Sherlock Holmes. Conan Doyle told everybody that Holmes was based on one of the men who taught him medicine in Edinburgh, but I'm positing a more mysterious figure. The book is written in that very dense Victorian style, and it's a way of taking apart his characters and putting them back togther in a more psychologically complex way. It also has a mystery plot, and an element of the supernatural - Doyle was a huge believer in spiritualism.'

Whatever the sources of Conan Doyle's fiction, Frost's own early writings were prompted by folklore: 'As a boy I found myself drawn to Arthurian legends, and then to Celtic mythology, and then further east into the mysticism of Asian religions.' (Hence Agent Cooper's otherwise baffling interest in Tibet.) The more formal beginning to his career came when he dropped out of his Theatre Studies course at Carnegie Tech in Pittsburgh, and went back to his childhood home of Los Angeles where he met a man called Steve Bochco.

'Steve went on to produce Hill Street Blues and LA Law but at the time - this was around 1974 - he was a story editor on something like Columbo. I showed him a screenplay I'd written about the assassination of Abraham Lincoln, and three weeks later I was writing television shows like The Six Million Dollar Man.' Disillusioned by the life after a year or so, he moved back to the midwest 'and worked as a playwright for three or four years, mostly for the Guthrie Theatre in Minneapolis.'

In 1979 he began to make documentaries for PBS, and then a couple of years later made a second and decisive return to Los Angeles, where he rejoined Steve Bochco and worked for three years as a writer and director on Hill Street Blues, turning out over 50 episodes. 'And on the very day I left Hill Street Blues I had lunch with John Schlesinger, who to my amazement offered me work on a film.' This was The Believers (1987), a hokey but engaging thriller about Voodoo cults in New York. 'What I really wanted at the time was a kind of Master's course in film-making, and John was very generous - I not only wrote the film but got involved in just about every aspect of it - from research to directing the second-unit.'

It was in the course of making The Believers that Frost first met and found a kindred spirit in David Lynch. Their agents brought them together over a script Frost had written about Marilyn Monroe, but they were soon coming up with less orthodox fare. 'We wrote a script together called One Saliva Bubble, very weird, which Dino de Laurentiis was going to produce. It was a comedy about a little town in Kansas which is hit by a ray from a secret government satellite and causes all kinds of strange reactions - people change identities and so on.'

While One Saliva Bubble sank, the duo began dreaming up a project which was called South Dakota, and then - when Frost pointed out they they wanted a lot of trees - North-West Passage. Finally, with the unexpected encouragement of ABC, it grew into Twin Peaks 'a behemoth which devoured two whole years of my life - I was working round the clock, sometimes turning out as many as six or seven revised scripts every ten days.' Small wonder that Frost has no ambition or desire ever to revive Peaks, though, curiously, his plans do involve one of his earliest inspirations for the show: Patrick McGoohan's similarly cultish series of the Sixties, The Prisoner.

'I'm a huge fan of that series; I was about 13 when I first saw it and it just blew my little mind to pieces.' Which is why Frost is now trying to negotiate for the rights to turn the series into a movie, updated to the present day and with a hero on the run from the CIA rather than some shadowy British intelligence outfit. Whether or not this feature will ever go into production remains uncertain, but in the meantime he will be kept busy on a television film about a murder trial in Minneapolis, and on a dramatised life of Crazy Horse. Cult series, murders, Native American lore: it all suggests that - to paraphrase Agent Cooper - there are dark and heinous things in Mark Frost's mind, and he plans to let us see them all.

On The Air will be screened by BBC 2; no date has been set.

(Photograph omitted)