On a chilly San Francisco afternoon, Neil Gaiman, the mop-topped British screenwriter, novelist, and comic-book writer, steps out of his limousine on Mission Street and into his past. Gaiman isn't usually prone to uttering things like, "Oh wow," and "My gosh," and "Oh my God," but utter them he does on a tour of a new exhibit at the Cartoon Art Museum. It's a retrospective of The Sandman, Gaiman's epic comic-book series that helped change the comic-book industry and helped make Gaiman what he is today: The face of a genre of storytelling that is very dark, very smart, and often very humorous. It says everything that Stephen King is a fan of The Sandman, and it says everything that, even 25 years after its creation, The Sandman holds up as high art.

From the beginning, The Sandman was a mix of memorable writing and memorable images — a collaboration with notable artists like Mike Dringenberg, Sam Kieth, and Dave McKean, who were just as edgy as Gaiman was. That's why Gaiman is so awestruck as he walks around "Grains of Sand: 25 Years of The Sandman" and sees the vision that he launched in 1989. With a collection that includes original proofs of pre-publication pages, the Cartoon Art Museum is featuring the comic-book equivalent of Old Testament scrolls. Many of those scrolls, long held in private hands, are new even to Gaiman.

"It's like traveling in time," Gaiman says as he steps from one framed hanging to the other. "It's remarkable, seeing it all in one place. You forget that there were 2,000 pages of Sandman. I have almost never seen the original art here. What I would get were black-and-white xeroxes, back in the day when there were xeroxes, or the art. ... Sometimes just the story was there."

The Sandman's central story centers around a lithe, brooding overseer named Dream, who wears dark robes and coats, and rules over the world of dreams. He's one of a septet of powerful god-like siblings, which includes his sister Death (who had her own couple of mini-series), and also Destiny, Destruction, Despair, Desire, and Delirium. They're a mixed-up family, especially Dream, who in the first issues of The Sandman is captured and held prisoner for 70 years. What's an angry god to do after his unjust incarceration? Revenge, of course, along with a bad attitude. In the series' third issue, titled "Dream a Little Dream of Me," Dream cares little about a dying, half-naked woman with infected skin and bedsores ("She will die soon. Painfully, I would imagine."), only to relent and ensure that her final moments are filled with dreams of love and desire. The artwork, which features odd panel sizes and noirish close-up shots of gore and danger, conveys the alienation and exasperation that fill Dream's life.

And then came groundbreaking issue eight from August 1989, "The Sound of Her Wings," which was drawn by Dringenberg and has Dream and Death hanging out in broad daylight, in what looks like New York's Washington Square Park. Pigeons fly about, and Dream feeds them. Teenagers play soccer nearby. Panel after panel, it's almost idyllic — a calm that's finally broken up when Death berates her brother for being so wistful, lamenting, and full of "could have beens," telling him, "You're utterly the stupidest, most self-centered, appallingest excuse for an anthropomorphic personification on this or any other plane!"

The Sandman, which was originally published by the DC Comics from 1989 to 1996 (Gaiman's series revived a forgotten older version), helped establish the modern market for comic books read by adults and those who wanted themes and plotlines meant for "mature audiences." Sex was in Gaiman's pages. Death, too, in all its dimensions. The character of Death was sexy, snappy, intellectual, and punkish. More than five million copies of The Sandman have been sold, and it's considered a fait accompli that a movie version will eventually emerge. In October, DC Comics began issuing a new Gaiman-written prequel series of that explains Dream's origins. To Gaiman, the whole series changed with issue No. 8.

"This is Mike [Dringenberg] changing the history of comics," Gaiman says as he looked at original pages of "The Sound of Her Wings." "This is where everything changed. Sandman up to that point was a horror comic that sort of recapitulated other DC horror comics. It existed in a very solid tradition. Sandman No. 8 — it found its voice. I found my voice. I think Mike found his voice. And we did something that was not like anything anybody had done before."

For The Sandman, Dringenberg's artistic influences included punk posters, band fliers, and "my own Dadaist tendencies towards visual non sequiturs," he says. "I felt a naturalistic approach would be better as a departure point to render the fantasia as truly fantastic."

By traditional museum standards of art, the art of comic books and graphic novels are often relegated to a lower tier, except in extreme cases, when someone like Roy Lichtenstein celebrates its power to enthrall and entertain. Gaiman cringes at art divisions that marginalize work like The Sandman.

"I've always felt that graphic novels and comics either were or could be art. There's never been a feeling that they weren't art or that there was anything art-deficient," says Gaiman. "Comics exist in the area that fine artists have problems with, because it is obviously commercial. Fine artists have problems with illustrators, let alone with comics. I've talked to people who say, 'Well, I wish I could be taken seriously by the art establishment, but my stuff is considered more illustration, even though it's a huge success.' And I say, 'Oh, you guys don't know. Wait till you start working in comics.'

"The joy of comics is an art style in which panel follows panel follows panel. There are 2,000 pages of Sandman. If we probably average six panels a page, you're talking 12,000 drawings. That's what it took to create Sandman, and as far as I'm concerned, a lot of that — it's art."