At quarter past noon Marie and Jim Kelly burst out of Crown Books yesterday with a freshly signed copy of Jimmy and Rosalynn Carter's new book and a message for the gate-crashing, celebrity-hungry throng on K Street: "It's a big thrill! Truly! And they look wunnn-der-ful!"

As the elderly couple emerged, victors after a three-hour marathon of line-waiting and determination, the crowd parted grudgingly, as if no one should be permitted to leave until every one of the roughly 500 oglers could be squeezed into the bookstore for a brush with history.

Tense and expressionless Secret Service men bolted up and down the aisles of the bookstore, one muttering solemnly about "missed cues," another snapping at stray oglers who wouldn't stay in line.

A D.C. policeman, engulfed by the crosscurrents of humanity, just listened helplessly as his radio emitted a static-scratched message: " ... Crown Books ... people ... waiting for autographs ..."

Somebody was making jokes about peanut oil and cholesterol.

Somebody was apologizing for jabbing her camera into another person's back.

Someone had caught a glimpse of the arrival and declared that "Rosalynn is pretty."

The trail of expectant admirers stretched around the corner of 21st and K streets, up toward Pennsylvania Avenue and mysteriously hung a left at the underground Colonial Parking lot on 21st Street ( "I dunno why," said one of the garage attendants), and trickled down the ramp onto the first subterranean level.

Earlier efforts by Crown employes to segregate book buyers from book owners had utterly perished. Cries of "Have you bought your book yet?" and "Has everyone bought the book?" gave way to "Hey, they're skipping the line" and "How'd she get in there?"

It was the kind of marginal crowd control that gives one a taste of life on the edge.

Inside, nestled between "Religion and Philosophy" and "Reference" books sat the authors of "Everything to Gain: Making the Most of the Rest of Your Life." Above them, Shakespeare's "All's Well That Ends Well." To their right, "The Bantam Instant Speller."

This two-hour chapter in the Carters' life-after-the-White-House was filled with people wanting only to say the simplest of things: "I voted for you every time." "It's a pleasure t'meet you." "We've been admirers for a long time." "I'm so glad I got to meet you." "I met you at a fund-raising dinner." "We miss you." "You're lookin' good."

"We appreciate your coming here 15 minutes early," one woman said.

"Well, we were over at NPR and they told us there were long lines, so we cut our lunch hour short," Jimmy Carter said.

"My mother worked in your campaign," said another woman.

"Where?" he asked, pulling his blue eyes up from the open book and the newly penned autograph.

"Here in Washington," she said.

"We always did well in Washington," he said gently.

Down the aisle, along the wall of discounted New York Times hardcover and paperback best-sellers, came another book and another owner:

"My father was in the Naval Academy with you ... "

"What's his name? ... What's he doing now?"

A mild-mannered Crown employe took the books from the well-wishers, opened and handed them to Jimmy Carter, who scrawled a hasty JCarter on the white paper with his black felt-tip pen. He slid the book to Rosalynn, who, beneath her husband's signature, put her own careful, steady script "Rosalynn Carter."

From him, the gentle southern burblings: "Hello ... Right on ... How are you? ... Next? ... Right on ... Nice to see you ... "

From her, quiet diligence and a smiling "Thank you."

"I have to concentrate," Rosalynn said, "Or else I write what I'm saying."

"I was gonna bring him a sandwich," chirped one woman to the unflinching face of a Secret Service man. "So he'd stay a little longer."

Jimmy, looking up, smiled and said, "I stayed long enough to get to your book."

Chip Bishop, who worked on both of Carter's campaigns -- first as an advance man and then as a scheduler -- was there to say hello to a man he called his "personal and political hero."

"It feels good," Bishop said. "I'm thrilled to see him again. I've sent a copy of the book to my parents, who are retired and not doing much of anything. I thought it would help."

Harold Mays, another line-waiter, was comfortable with the idea of an ex-president promoting his work in a discount bookstore.

"It only proves what I thought -- that he's a man of the people," he said. "I believe in what he stood for and it's sort of an exciting thing to see him come back. He's a plain man ... President Carter and Mrs. Carter are very humane and loving people and this kind of proves it."

A baby squealed. Someone said, "Thank you for sharing your story with us." Rosalynn wiped her cheeks and brow with a napkin and said, "Suddenly, I'm feeling so hot." Jimmy took a sip from his glass of pop, smiled, and dropped his pen to the next book.