Howard Hughes "had a powerful kind of hold over me," says Michael Drosnin, who spent seven years hiding out to write "Citizen Hughes," a best seller based on what he says are the reclusive billionaire's own memoranda.

"There were times when I was writing in a trance -- I couldn't get the words down fast enough. It was as if I was the medium through which Hughes spoke. There were times when I was there. I would write with such a feeling of certainty, I had to go back over it to be sure I hadn't gone beyond what I had evidence for. And sometimes I was able to confirm that it had actually happened that way.

"It was a spooky experience. It wasn't ESP, it was just that I was so immersed in the material I could guess what was right. But when the identification was too strong, I'd look at my bank book and know I was not Howard Hughes."

In the book, Drosnin describes Hughes as he was when he holed up in the Desert Inn Hotel in Las Vegas, from November 1966 to November 1970:

. . . There was Hughes, naked in his bedroom, unwashed and disheveled, his hair halfway down his back, sprawled out on a paper-towel insulated bed, staring at his overworked television . . .

The real Mr. Big was surrounded only by filth and disorder. Mountains of old newspapers, brittle with age, spread in an ever-widening semicircle on the floor around his bed, creeped under the furniture, and spilled into the corners of his cramped fifteen-by-seventeen foot room, mixed together haphazardly with other debris -- rolls of blue prints, maps, TV Guides, aviation magazines and various unidentified objects.

A narrow path had been cleared from his bed to the bathroom, then lined with paper towels, but the tide of trash overran even that, topped off by numberless wads of used Kleenex the billionaire wielded to wipe off everything within reach, then casually cast upon the accumulated rubbish . . . united in a common thick layer of dust that settled in permanently over the years. The room was never cleaned . . .

Amid this incredible clutter, set apart in pristine splendor, stood stack after stack of neatly piled documents. They covered every available surface. Thousands of yellow legal-pad pages and white typewritten memos piled with absolute precision on the dresser, two night tables, and an overstuffed armchair, all within easy reach of Hughes on his bed. He compulsively stacked and restacked these papers, often for hours at a time, taking a sheaf and whacking them down to align one side, then another, endlessly repeating the process until not a page was a millimeter out of place. That was vital.

These special papers were the instruments of his power.

For the four years Howard Hughes made his Last Stand in Las Vegas, he commanded his empire by correspondence. It was the only time in his life that the world's most secretive man regularly risked writing down his orders, plans, thoughts, fears and desires . . .

A briefcase full of memos -- a sample of the 10,000 documents, 3,000 identified by experts as in Hughes' handwriting, according to Drosnin -- on which he based "Citizen Hughes," lies on a table in the Embassy Row Hotel cafe. Drosnin, 37, a former reporter for The Washington Post and the Wall Street Journal, reaches out from time to time to pat them, to make sure they are still there.

Drosnin says these internal documents of the Hughes empire, from the supposedly impregnable Hughes headquarters at 7000 Romaine St. in Hollywood, Calif., were stolen in June 1974. Drosnin says he solved the robbery -- which he believes was staged by the Hughes organization -- and found the man hired to steal the papers.

The yellow legal-pad pages, a day-to-day record of Hughes' thoughts during his years of isolation, according to Drosnin, are full of the bizarre billionaire's secrets. In these memos Hughes proposes buying not only ABC-TV but the U.S. government. His objectives: to ban atomic testing (especially in Nevada, where he hibernated), to prevent black men from touching white women on television, and to improve the selection of movies on the late, late show.

Hughes attached equal weight to all these aims, says Drosnin.

And the books claims that the papers enlighten other matters:

* Prior to the Watergate break-in, President Nixon feared that then-Democratic Committee chairman Larry O'Brien knew about a Hughes $100,000 payoff. Drosnin notes that Bob Haldeman said the famous 18 1/2-minute gap in the Nixon tapes obliterated revelations about Hughes' connection to Watergate.

* During the Johnson administration, Hughes wrote to Robert Maheu, his close associate: "I think you should try to determine who is the real, honest-to-God bagman at the White House. And please don't be frightened away by the enormity of the thought . . . Now I dont know whom you have to approach, but there is somebody, take my word for it."

* Hughes, in a memo, proposed a play-by-phone scheme to make himself bookie to the entire world: ". . . Men, simply by nature, like to show off. I can just see some minor league V.I.P. out to dinner with some attractive young protagonist of the opposite sex, and he picks up the phone, brought to his table at Twenty-one, and he makes a five or ten thousand dollar bet over the phone. Then he turns to his girl and says: 'Well, I just won ten thousand in Vegas -- let's spend it.' "

"Howard Hughes had such an overwhelming personality," Drosnin says, that "even though he was dead I felt as though he possessed me. At one point I was so overwhelmed I wanted to keep his secrets. I wrote 'Citizen Hughes' as an act of exorcism."

Half the book is in Hughes' own words, as "an unwilling autobiographer." He was the perfect collaborator for Drosnin, because "though he was hell to live with, he had his work done before I started and he didn't want half the royalties."

Drosnin holds tightly to the yellow papers as he talks.

"While I was writing the book," Drosnin says, "even though I was living under an assumed name at an address even my publisher didn't have, I'd never keep the originals where I was. I kept them at another place entirely. I was never sure who would come after me or come after the papers . . .

"But every once in a while, I would go to them and take out and hold the papers he actually wrote. The papers had a sort of a Talmudic power. It was a way of getting myself excited all over again."

He says Hughes "was a lucid writer. Even when talking about the most insane of things, he expresses himself well and forcefully." Hughes "jumps out from the papers. He certainly pulled me right in. He was such an innocent. Inside this atrocious old man was the innocence of a child. He wasn't like Nixon, who knew what he was doing. Hughes was like an antivillain in a world of antiheroes. Who else would ask his assistant to find the bag man at the White House?"

The memos, most from Hughes to Maheu, are "letters of love and loss," Drosnin says, "reflecting a sort of marriage, though the two never met." The documents also show "a glimpse into the true nature of power. Clearly, Hughes was driven to power by fear."

. . . The memos were at once a cold-blooded tale of an entire nation's corruption and an intimate journal of one man's descent into madness. The great secret that Howard Hughes had kept hidden was not this or that scandal, not this payoff or that shady deal, but something far more sweeping and far more frightening -- the true nature of power in America . . .

He was an American folk hero, a man who had lived first the dream then the nightmare -- in that sense, perhaps the single most representative American of the twentieth century . . .

Drosnin talks enthusiastically of his seven-year ordeal of writing and researching the book, though there are questions he doesn't want to discuss, such as how Howard Hughes broke up his marriage.

His obsession -- he calls it "this adventure" -- began eight years ago. Drosnin was assigned by New Times magazine to do a story about the Glomar Explorer. The ship was allegedly a deep-sea mining vessel, owned by Hughes. Actually, Hughes' interest was only a cover story.

The ship belonged to the CIA, which used it to recover a Soviet submarine sunk in the Pacific about the time of the break-in at Hughes' Hollywood headquarters. The CIA was concerned that the stolen documents would blow the Hughes cover just as the agency was preparing to raise the submarine, according to Drosnin.

"I had assumed the break-in had been solved, that the papers had been found," Drosnin says. "I made a half a dozen telephone calls from New York. In those half a dozen phone calls, I was turning up information the authorities hadn't touched. There was supposedly this massive FBI investigation which indeed did take place, a million-dollar CIA buy-back bid to get the documents.

"Asking questions any cub reporter would ask, I was reaching people who'd never been contacted by the authorities and turning up information they had apparently never found. I knew something was terribly wrong, and very interesting. It was clear the case had never been solved -- the burglars had never been caught and the papers had never been found -- and no one was looking for them anymore.

"I didn't then know why. I later discovered why from documents I got from the FBI and CIA through the Freedom of Information Act. There came a point when the FBI and the CIA were actually afraid to find those papers. Incredible -- it was like the last scene in the 'Raiders of the Lost Ark,' when they put the ark away. Secrets best left untold. Watergate was like that.

"When I realized this was virgin territory, that no one was looking for the papers," Drosnin says, "I became obsessed with it."

Soon he believed he knew not only who committed the break-in but who had the papers.

The first time Drosnin met the Pro, as he called him in the book, the Pro had a gun stuck in the belt of his pants. "Not concealed," Drosnin says. "He wanted me to see it. He was a professional safecracker. He was a man brought in to stage this burglary.

"He was never supposed to end up with the papers. I don't know who was ultimately behind the break-in, but the weight of evidence suggests it was persons within the Hughes organization who were trying to safeguard these papers from subpoenas by staging a fake break-in."

Drosnin says because he had once gone to jail rather than reveal a news source, the Pro trusted him and eventually showed him the papers. Drosnin says he paid the Pro nothing, though the man had originally hoped to use the papers for blackmail -- and a fantasy, a chance to play poker with Howard Hughes. Soon Drosnin realized the Pro thought the papers were the biggest thing he'd ever stolen and wanted someone to tell about his great heist.

The Pro removed the documents from their hiding place between two walls and stashed them in a motel room. There Drosnin read them in a compulsive, sleepless marathon. The Pro allowed him to photograph all of Hughes' handwritten memos and to photocopy all the typed memoranda by Hughes and his aides. He saw "names like Nixon, Johnson, Humphrey, Kennedy, numbers in the millions, talk of dealings with the mafioso."

The Pro also allowed Drosnin to take a sampling of the originals, "mainly for authentication purposes, but they are also fun to have for show and tell . . . I wanted to make damn sure nobody seized them from me. There was a massive amount of litigation about the Hughes estate. Both sides of all these cases wanted me and these documents. I didn't want to be drawn into that, or I would have spent these seven years in various courtrooms and various jails."

Howard Hughes took over the writer's life. Drosnin cut himself off from all but a few friends and family while doing 1,000 interviews to flesh out and confirm the story. He changed his name to Michael Howard, a reference not only to his subject but to outlaw Jesse James, who used Howard as a nom de flight. He moved to another apartment. He stuck strictly to the "don't call me, I'll call you" rule.

A $100,000 advance from Holt, Rinehart and Winston -- after extensive scrutiny by CBS (the parent company) lawyers and a team of handwriting experts -- supported Drosnin and paid for his research. "I figured it averaged out to less than minimum wage per hour," he says.

The book was finished six months ago, and today Drosnin is making the talk circuit, wearing his first new suit in 12 years. But even now he isn't free of the man he described as looking like this on April 3, 1976:

. . . When awake, he refused to eat. His weight had dropped to 94 pounds. His six-foot-four inch frame had shrunk three inches. His brittle bones showed plainly through his parchmentlike skin. His left shoulder was bruised and swollen. He had a gaping wound on the side of his head where he had sheared off an old tumor a few weeks earlier when he fell out of bed. He had four broken needle points embedded in his right arm, another in his left. And inside, his atrophied kidneys, destroyed by a quarter century of drug abuse, were killing him.

Two days later he died in an airplane, 3,000 feet up. The story had ended for Howard Hughes. Not long after, it began for Michael Drosnin.