The first time I met Barker, in 1985, he was a charmingly enthusiastic 33-year-old unknown who'd moved from Liverpool to London. Thirteen years later, he owns three homes in Beverly Hills. His entree to pop culture is so pervasive he recently appeared on The Donny and Marie Show. They thought he was the Devil. But as he talks in his Knightsbridge hotel, his boyishness seems untouched. His latest novel, Galilee, is a saga of two entwined families, the semi-divine Barbarossas and the Kennedy-like Gearies. It includes a conceit only a writer with concerns more important than writing would dare. Parts of it are written in the style of American soaps. Barker means to tempt in the mass public who sate their dreams on America's most popular dramatic form, then feed them something stronger. "It's worked, too!" he chortles.
Barker says he wants his work to reach out to the world, to infect his readers with the teenage fervour he still feels himself. But, paradoxically, writing removes him from the world. Galilee's narrator, a writer, is paralysed. The prolific Barker too must feel desk-bound; letting his life wither to put his visions on the page. "Writing consumes," he says, "but what is the alternative? The alternative I don't think would be 'let's go out clubbing'. The alternative would be I'd be fucked up. The alternative is probably going crazy. The business of writing helps me think more clearly. There's something therapeutic about it. I have a fierce sense of purpose when I'm writing, a sense of purpose which does not exist elsewhere in my life."
The barrier between imagining and living, wafer-thin in so much of his work, once came close to breaking for Barker. Finishing the 1,000-page Imajica in 1991 in a London house stripped of all his belongings, a kind of limbo before he left for America, he was terrified he wouldn't finish, that the book would beat him; and he was ecstatic, pausing in his scribbling only to sleep. As he envisioned the haunts he was abandoning, the London outside his door fell away. Encoding metaphysical concepts, the physical became banal. "I thought, 'Maybe I'll never write anything else.' It felt like an end-game," he says. "I might never have left that room."
For all the risks he took then, the logic of Barker's work suggests he may one day go further. The transcendence his books offer to humanity, hidden in reality-cracks, fissures and coma-states, comes down, in the end, to writing. In The Book of Blood, a boy has his skin inscribed with stories. In Everville, the heroine Tesla's spirit ascends into a computer databank of narratives. She dissolves into stories. It's almost as if Barker's writing is tempting him to do the same - to enter his visions, and never come back.
"I think it's true," he says. "I think in Tesla's case, there's something wonderful about her presence in story - that she's been released. And I can trace this in other places. I would also say the Candyman is aware strongly of this. His great temptation is to say, 'Come be a legend with me. You won't have to feel anything. But you will have the power of being a story. Lovers will cling together more closely when they hear about you. You'll be something which is used to put children to sleep at night.'" Is it a hope he entertains for himself? "I think the hope as a writer, eventually, is that you become invisible. You become a glorious redundancy."
If anything keeps Barker solid as he wanders through his imagination in the Californian sun, it may be the stories he tells to himself. Weaveworld's heroes saved a world by remembering it. Barker does the same for his British childhood. Three vistas in particular define him so deeply he's set them down in his books, as if to preserve them: a holiday island in the Hebrides; a Welsh farmhouse, with a view from a window he remembers like a primal scene; and, most of all, the thread which weaves through his dreams: the Mersey.
"The river, and the sense that it delivers you out into a larger place, a place I did not get to see until a lot later, carries incredible romance," he says. "That sense of a world filled with strange names, that began at the end of the river. When I think about the world, I think about the sea. I think the sea, whether the dream-sea of The Great and Secret Show, or the physical sea, as it appears in many of my books, is always the means of carrying me away. My flight into fantasy as a kid was a flight from the world. Now, those same mechanisms have become a way back."
'Galilee' is out this week (HarperCollins pounds 17.99)