Arkady Nikolaevich Shevchenko, former Soviet diplomat and current famous writer, grabs the reporter's hand and pulls it up the staircase.

"Arkady, don't you dare take him up there!" cries his wife of six years, the former Elaine Bissell Jackson.

Shevchenko toils upward. Finally he nudges the reporter into a shelf-lined sanctum containing a big brown desk. "Here is where I wrote it," he announces with a flourish. "I know you want to see for your story. I understand these things. It's very American, of course."

The author of "Breaking With Moscow," the memoirs of a Soviet henchman turned Western spy, explodes in a buttery laugh. It is, he says, only the second time that a reporter has been permitted inside the Shevchenko household ("just memorize the address, don't write it down," his wife had instructed), a rambling brick affair somewhere in Northwest Washington.

"First was Mike Wallace," he says, and laughs again.

The laugh, for Shevchenko, is a matter of punctuation -- of equal utility whether he is describing his cameo role at age 18 in a propaganda film titled "Meeting at Elbe" ("I play a very small part as a kind of aide to someone big, carrying the coat for Vera Orlova, who was the Russian Elizabeth Taylor!") or discussing his aspirations to produce a scholarly volume on the formulation of Soviet foreign policy ("If the Soviets will not kill me first!") or simply inviting a reporter to a book party ("Bring your wife, or, like Americans do, bring your girlfriend instead!").

"American mass media are so much interested in personal life," he says, smiling a thin smile. It's a couple of hours before he is to give a talk at the National Press Club, billed as "A View From the Kremlin." "We don't like to wash our dirty linen in public. American mass media have a bad habit of looking always for the dirty story."

Shevchenko, the celebrity defector, ought to know. In the last seven years, he has parlayed his break with Moscow into a snug berth on American television as Kremlinologist-in-residence, a prestigious post teaching at the American Foreign Service Institute, a dizzying itinerary on the lecture circuit (with fees topping $12,000, says his agent Joe Cosby), and, now, a book already in its third printing before the official March 1 publication date at Knopf.

Having revealed his heretofore secret stint as a Western spy, Shevchenko is once again riding the wave. It started two weeks ago with the lead position on CBS' "60 Minutes" and book excerpts in Time magazine, roared ahead with ABC's "Good Morning America" and NBC's "Today" show, surged again last week with "Donahue" and was still going strong yesterday with a big splash in The New York Times Book Review.

"We're talking about someone," marvels Cosby, who represents such tongues-for-hire as Kurt Vonnegut and Carl Sagan, "who has gone from communism to tax shelters in just seven years. And you should see him when he's negotiating a contract. He's tough -- a lot tougher than Sagan."

Shevchenko is sitting tieless on a love seat next to a marble end table, smoking menthol cigarettes. His hazel eyes glitter behind broad-lensed glasses. The "vertical scar on left ankle" -- duly noted in his Permit to Re-enter the United States, the travel document he must use instead of a U.S. passport -- is hidden, presumably, by his soft black boot.

"I knew too much," Shevchenko says. "I think the Soviets would put me in a mental institution. They treat Sakharov better than they would treat me."

His wife, a soft-spoken native of North Carolina, sits beside him. "We change our telephone number from time to time, but the Soviets can still listen to us," she says. "The police know where we live and the CIA is watching us, too. But I think his high visibility also helps a lot to protect him."

Currently a resident alien, he says he must wait another year before he can apply for U.S. citizenship -- 2 1/2 years longer than usual because of his former membership in the Communist Party.

"I could ask Congress for a private bill but I don't want to do that," says Shevchenko, who is a trustee of the Jamestown Foundation, a Washington-based group established to aid high-level eastern bloc defectors.

"It's a great feeling I get from the people, to know that they are behind me," he says, sounding for the moment like an Olympic gold-medalist (as played, perhaps, by Peter Lorre). "I really believe that sincerely . . .

"I hear some people call me 'the spy who came in from the cold to get to the gold.' But I had much more gold before the cold. You see the lawn?" he says, gesturing toward a white-curtained window. "In Russia I had a dacha with woods all around and a lawn for half a mile."

He was born 54 years ago in the Ukraine, a doctor's son who dashed up the rungs of Soviet society -- where "Machiavelli would have been a student, not a professor," as he writes in his book -- to become a privileged and powerful man, a prote'ge' to Foreign Minister Andrei Gromyko.

Maybe he could have shown Machiavelli a thing or two?

"Perhaps so!" he agrees with a laugh.

Why he decided to give it all up is still a matter of speculation. Shevchenko says he did it for freedom. Others have suggested that he might have been blackmailed into it by the CIA -- a charge he vehemently denies.

"The trouble in the intelligence world is you never know who to believe," says a former newspaper correspondent to Moscow who asks for anonymity. "For all I know, the Kremlin could be laughing their sweet little hearts out."

"He betrayed his country, and that speaks for itself," scoffs the Soviet Embassy's press spokesman, Michael Lysenko.

Shevchenko has lived in and out of the spotlight since April 1978, when he became the highest ranking Soviet official ever to defect while serving as the Soviet mission's undersecretary to the United Nations. A month later, his first wife Lina, who had been spirited by the Soviets to Moscow along with their teen-age daughter, died of a drug overdose (a suicide, the Russians said). A few months after that, a call girl named Judy Chavez announced that Shevchenko had paid her for companionship with money from the CIA. Shevchenko admitted the relationship, but denied that the money, some $40,000, had come from the CIA.

"I lived a nightmare for a few months," he says. "It is bad taste for American press to revive the Chavez incident. Some of you, even in the presence of Elaine, do that."

Shevchenko's life has calmed down considerably since he met and, after a six-week courtship, married Elaine Jackson in December 1978. A veteran court reporter, she helped him write his book -- correcting such mistakes as his habitual substitution of "wives" for "views," as in, "The ambassador and I exchanged wives on the subject of detente."

"I just thought he was fascinating," she says. "I had never met anybody from the Soviet Union before."

It is time to head for the press club, where Shevchenko will banter with guests at a cocktail reception ("Who's going to play you in the movie?" "Myself -- if I can change my face and do something with my hair") and talk about the Soviet-American arms negotiations in Geneva, urging the Americans to be wary. Before he gets out of the taxi at the National Press Building, he asks the driver for a receipt.

"This is very American, too!" he says, as he pockets the receipt with another explosive laugh.