HOW DOES A nice man like you wind up scaring everybody half to death? was the super-bright first question I threw at the author of Ghost Story . Are you in it just for the money? (Parenthetically, the money includes a big book-club sale, whopping paperback bread and film farm, and a good head start for the Coward-McCann hardcover edition.)

Straub, polite although jet-lagged (he'd just flown in from London), gave the question a moment's thought. "The way my friend Stephen King (author of Carrie, Salem's Lot. The Stand ) always answers that is to say, 'I have a marketable obsession.' I think that's a reasonable starting point. Your own imagination takes you places that do well in book-stores. All writers want that, anyhow."

I comment that Straub has an "evil imagination." "Well, I have an imagination; most people do," he counters. "I think that almost anybody can find in his imagination really dark places and can spin them out. The more experience at it you have, the better you become. In part, it's also a matter of techniques, knowing how to time the surprises in a book to get the maximum effect.

The plot of Ghost Story involves a struggle between living people and protean ghosts or ghostly beings who commit murder, yet the struggle is not between "good" and "evil." There is no God, no Satan. "You're right," Straub agrees. "It has no religious dimension. It's much more entertainment. Also, I personally don't have any interest in religion. I don't know enough about it; I don't feel it, so I'd have to work, it up too much to plug it into a book.

"Inasmuch as I thought about the prehistory of these ghostly creatures, I thought of them as being parallel to mankind, pursuing their own secret history at the same time that mankind goes on with its public history. The reason that I had the plot come down to creatures like that is that I realized that most supernatural books do in fact come down to creatures that change shapes, become different things.

"Men turn into wolves or bats. A witch is kind of a transformation of a woman. So I thought this was kind of a 'scoop' on the supernatural, to find the 'ur-vampire' and the 'ur-werewolf.' Folklore is loaded with men who turn into foxes and speak, with all sorts of shape-changing creatures. Yet what interested me when I was working on the novel was far more a matter of inventive imagination than of any folklorist underpinnings.

"My chief 'literary' aim, insofar as I had a purpose beyond simple entertainment, was that I wanted to reflect back on other stories of this sort in American writing, and sort of play games with older stories in that field -- one based on my responses to certain stories by Hawthorne and Poe and Henry James. So when my character Sears James tells a story in my novel he tells a roughed-up version of The Turn of the Screw ."

Has Straub himself ever had anything like a supernatural experience? "Well, I'm scared a lot." he smiles. What frightens him? "Things I imagine. It isn't anything specific. I'm not afraid of black cats, although I don't ever walk under ladders. But sometimes, sitting alone, I'll think of something that scares me." You frighten yourself? "I think that in the main people do frighten themselves." Were you frightened when you wrote Ghost Story ? "No, because I was having too much fun, although I did give myself a really salutory shock at one point, when I wrote what I think is the scariest bit in the book. It's a moment that's so standard in novels of this sort that it's almost a quotation, like jazz musicians quote songs.

"Two young boys go up the stairs in a threatening house, and the tension and fear build and suddenly -- from the bottom of the stairs -- 'Hello, boys.' When I wrote 'Hello, boys,' I practically jumped out of my chair. I thought, that's it! When I reached that point in that scene, I knew that the entire rest of the book was going to fall into shape and that it was going to move along at a very good clip. So I relaxed and got out of the way of the story and let it roll."

So what you're saying is that you wrote a ghost-story potboiler. Straub looks a little uncomfortable, but maybe it's the jet-lag. "I call it an entertainment. It could be seen like that, as long as no derogatory meaning is attached to the word 'potboiler.' "We exchange a smile. "Of course, it is attached," he concedes."I did want to write a popular book. I would have been foolish, I think, to try to do anything else. But, in the main, what I sort of see as my goal -- perhaps an awfully pretentious one -- is to give a greater seriousness to stuff of this kind, and to treat it with more intelligence, maybe, and more care than it usually is treated.

When I knocked at my imagination, and I opened it up, that's the stuff that came out, and I hadn't expected it to. So, being saddled with it, so to speak, I wanted to treat it as though I were writing mainstream, serious fiction." CAPTION: Picture, Peter Straub by Jerry Bauer